Sensing device having automatic mode selection

ABSTRACT

A sensing device for interaction with a surface, said sensing device having automatic mode selection, said sensing device comprising: an image sensor for imaging the surface and generating image data; a motion sensor configured for determining one or more relative position changes of the sensing device; a processor configured for: receiving the image data; and automatically selecting, using said image data, either an interaction mode or a cursor mode for said sensing device; and communication means for transmitting either interaction data or cursor data to a computer system, dependent on said selected mode, wherein said processor is configured to: select the interaction mode and generate interaction data from the image data if said image data indicates that said sensing device is interacting with a first surface having a position-coding pattern disposed thereon, said interaction data being indicative of at least one absolute location of the sensing device relative to the surface; and select the cursor mode if said image data indicates that said sensing device is interacting with a second surface lacking a position-coding pattern, said cursor data being indicative of said one or more relative position changes of the sensing device.

FIELD OF INVENTION

The present invention relates to a method and system for reading aposition-coding pattern disposed on a surface. It has been developedprimarily to improve the functionality of sensing device used forreading the position-coding pattern.

COPENDING

The following applications have been filed by the Applicantsimultaneously with the present application:

NPZ025US NPZ026US NPZ028US NPZ029US NPZ030US NPZ031US

The disclosures of these co-pending applications are incorporated hereinby reference. The above applications have been identified by theirfiling docket number, which will be substituted with the correspondingapplication number, once assigned.

CROSS REFERENCES

The following patents or patent applications filed by the applicant orassignee of the present invention are hereby incorporated bycross-reference.

6276850 6520631 6158907 6539180 6270177 6405055 6628430 6835135 66265296981769 7125338 7125337 7136186 7286260 7145689 7130075 7081974 71770557209257 6443555 7161715 7154632 7158258 7148993 7075684 10/94390510/943906 10/943904 10/943903 10/943902 6966659 6988841 7077748 72556467070270 7014307 7158809 7217048 11/225172 11/255942 11/329039 11/3290407271829 11/442189 11/474280 11/483061 11/503078 11/520735 11/50585811/525850 11/583870 11/592983 11/592208 11/601828 11/635482 11/63552610/466440 7215441 11/650545 11/653241 11/653240 7056040 694233411/706300 11/740265 11/737720 11/739056 11/740204 11/740223 11/75355711/750285 11758648 11/778559 11834634 11/838878 11845669 6799853 72378966749301 10/451722 7137678 7252379 7144107 10/503900 10/503898 10/5038977220068 7270410 7241005 7108437 7140792 10/503922 7224274 10/50391710/503918 10/503925 10/503927 10/503928 10/503929 10/503885 71953257229164 7150523 10/503889 7154580 6906778 7167158 7128269 66885286986613 6641315 7278702 10/503891 7150524 7155395 6915140 69992066795651 6883910 7118481 7136198 7092130 6786661 6808325 10/92036810/920284 7219990 10/920283 6750901 6476863 6788336 6322181 65978176227648 6727948 6690419 10/470947 6619654 6969145 6679582 10/4709426568670 6866373 7280247 7008044 6742871 6966628 6644781 6969143 67670766834933 6692113 6913344 6727951 7128395 7036911 7032995 6969151 69554246969162 10/919249 6942315 11/006577 7234797 6986563 7295211 11/0454427286162 7283159 7077330 6196541 11/149389 11/185725 7226144 11/2023447267428 11/248423 11/248422 7093929 11/282769 11/330060 11/4421117290862 11/499806 11/499710 6195150 11749156 11782588 11/85443511/853817 11/935958 11924608 6362868 11970993 6831681 6431669 63628696472052 6356715 6894694 6636216 6366693 6329990 6459495 6137500 66904167050143 6398328 7110024 6431704 6879341 6415054 6665454 6542645 64868866381361 6317192 6850274 09/113054 6646757 6624848 6357135 62719316353772 6106147 6665008 6304291 6305770 6289262 6315200 6217165 64966546859225 6924835 6647369 6943830 09/693317 7021745 6712453 64609716428147 6416170 6402300 6464340 6612687 6412912 6447099 6837567 65059137128845 6733684 7249108 6566858 6331946 6246970 6442525 09/51738409/505951 6374354 7246098 6816968 6757832 6334190 6745331 724910910/203559 7197642 7093139 10/636263 10/636283 10/866608 721003810/902883 10/940653 10/942858 11/706329 11/757385 11/758642 71198367283162 7286169 10/636285 7170652 6967750 6995876 7099051 71721917243916 7222845 11/239232 7285227 7063940 11/107942 7193734 70867247090337 7278723 7140717 11/190902 11/209711 7256824 7140726 71565127186499 11/478585 11/525862 11/540574 11/583875 11/592181 675094411/599336 7291447 11744183 11/758646 11/778561 11/839532 11/83887411/853021 11/869710 11/868531 11927403 11951960 10/636225 69852076773874 6650836 10/666495 10/636224 7250975 7295343 6880929 72361887236187 7155394 10/636219 10/636223 7055927 6986562 7052103 731284510/656281 10/656791 10/666124 10/683217 7289142 7095533 6914686 68962526820871 6834851 6848686 6830246 6851671 10/729098 7092011 718740410/729159 10/753458 6878299 6929348 6921154 10/780625 10/804042 691334610/831238 10/831237 10/831239 10/831240 10/831241 10/831234 10/8312337246897 7077515 10/831235 10/853336 10/853117 10/853659 10/8536816913875 7021758 7033017 7161709 7099033 7147294 7156494 11/01202411/011925 7032998 7044585 7296867 6994424 11/006787 7258435 70972637001012 7004568 7040738 7188933 7027080 7025446 6991321 7131715 72613927207647 7182435 7097285 11/228410 7097284 7083264 7147304 72322037156498 7201471 11/501772 11/503084 11/513073 7210764 11/63552411/706379 11/730386 11/730784 11/753568 11/782591 11/859783 67104576775906 6507099 7221043 7107674 7154172 11/442400 7247941 11/73654011/758644 11/940304 6530339 6631897 6851667 6830243 6860479 69974527000913 7204482 11/212759 11/281679 11/730409 6238044 6425661 11/0037867258417 7293853 11/003334 7270395 11/003404 11/003419 11/003700 72554197284819 7229148 7258416 7273263 7270393 6984017 11/003699 11/0714737156497 11/601670 11748482 11/778563 11/779851 11/778574 11/85381611/853814 11/853786 11/872037 11/856694 11965703 11/003463 11/00370111/003683 11/003614 7284820 11/003684 7246875 11/003617 11/76476011853777 11955354 11/293800 11/293802 11/293801 11/293808 11/29380911/482975 11/482970 11/482968 11/482972 11/482971 11/482969 64317776334664 6447113 7239407 6398359 6652089 6652090 7057759 6631986 71874707280235 11/501775 11744210 11/859784 6471331 6676250 6347864 64397046425700 6588952 6626515 6722758 6871937 11/060803 11/097266 11/09726711/685084 11/685086 11/685090 11/740925 11/763444 11/763443 1194684011961712 7249942 7206654 7162324 7162325 7231275 7146236 727884710/753499 6997698 7220112 7231276 10/753440 7220115 7195475 714424211/499746 11/501774 11/525858 11/545501 11/599335 11/706380 1173654511/736554 11/739047 11749159 11/739073 11/775160 11/853755 11/94029111934071 11951913 6786420 6827282 6948661 7073713 10/983060 70937627083108 7222799 7201319 11/442103 11/739071 11/518238 11/51828011/518244 11/518243 11/518242 7032899 6854724 11/084237 11/08424011/084238 11/357296 11/357298 11/357297 6350023 6318849 6592207 64396996312114 11/246676 11/246677 11/246678 11/246679 11/246680 11/24668111/246714 11/246713 11/246689 11/246671 11/246670 11/246669 11/24670411/246710 11/246688 11/246716 11/246715 11/246707 11/246706 11/24670511/246708 11/246693 11/246692 11/246696 11/246695 11/246694 11/48295811/482955 11/482962 11/482963 11/482956 11/482954 11/482974 11/48295711/482987 11/482959 11/482960 11/482961 11/482964 11/482965 11/48297611/482973 11/495815 11/495816 11/495817 60992635 60992637 6099264110/803074 10/803073 7040823 10/803076 10/803077 10/803078 10/80307910/922971 10/922970 10/922836 10/922842 10/922848 10/922843 71251857229226 11/513386 11/753559 10/815621 7243835 10/815630 10/81563710/815638 7251050 10/815642 7097094 7137549 10/815618 7156292 1173897410/815635 10/815647 10/815634 7137566 7131596 7128265 7207485 71973747175089 10/815617 10/815620 7178719 10/815613 7207483 7296737 727026610/815614 11/446240 11/488162 11/488163 11/488164 11/488167 11/48816811/488165 11/488166 7267273 11/834628 11/839497 11/944449 10/8156367128270 11/041650 11/041651 11/041652 11/041649 11/041610 1186325311863255 11/863257 11863258 11863262 11/041609 11/041626 11/04162711/041624 11/041625 11863268 11863269 11863270 11863271 1186327376584733 11/041556 11/041580 11/041723 11/041698 11/041648 1186326311863264 11863265 11863266 11863267 10/815609 7150398 7159777 10/8156107188769 7097106 7070110 7243849 11/442381 11/480957 11/764694 119574706227652 6213588 6213589 6231163 6247795 6394581 6244691 6257704 64161686220694 6257705 6247794 6234610 6247793 6264306 6241342 6247792 62643076254220 6234611 6302528 6283582 6239821 6338547 6247796 6557977 63906036362843 6293653 6312107 6227653 6234609 6238040 6188415 6227654 62099896247791 6336710 6217153 6416167 6243113 6283581 6247790 6260953 62674696588882 6742873 6918655 6547371 6938989 6598964 6923526 6273544 63090486420196 6443558 6439689 6378989 6848181 6634735 6299289 6299290 64256546902255 6623101 6406129 6505916 6457809 6550895 6457812 7152962 64281337216956 7080895 11/144844 7182437 11/599341 11/635533 11/60797611/607975 11/607999 11/607980 11/607979 11/607978 11/735961 11/68507411/696126 11/696144 11/696650 11/763446 6224780 6235212 6280643 62841476214244 6071750 6267905 6251298 6258285 6225138 6241904 6299786 68667896231773 6190931 6248249 6290862 6241906 6565762 6241905 6451216 62317726274056 6290861 6248248 6306671 6331258 6110754 6294101 6416679 62648496254793 6245246 6855264 6235211 6491833 6264850 6258284 6312615 62286686180427 6171875 6267904 6245247 6315914 7169316 6526658 721076711/056146 11/635523 6665094 6450605 6512596 6654144 7125090 66870227072076 7092125 7215443 7136195 7077494 6877834 6969139 10/6362277283280 6912067 7277205 7154637 10/636230 7070251 6851782 10/63621110/636247 6843545 7079286 7064867 7065247 7027177 7218415 70648736954276 7061644 7092127 7059695 10/990382 7177052 7270394 11/1242317188921 7187469 7196820 11/281445 7283281 7251051 7245399 11/52491111/640267 11/706297 11/730387 11/737142 11/764729 11/834637 11/85301911/863239 11/305274 11/305273 11/305275 11/305152 11/305158 11/3050086231148 6293658 6614560 6238033 6312070 6238111 6378970 6196739 62701826152619 7006143 6876394 6738096 6970186 6287028 6412993 11/03314511/102845 11/102861 11/248421 11/672878 7204941 7282164 10/81562811845672 7278727 10/913373 10/913374 10/913372 7138391 7153956 10/91338010/913379 10/913376 7122076 7148345 11/172816 11/172815 11/17281411/482990 11/482986 11/482985 11/454899 11/583942 11/592990 1184936011/831961 11/831962 11/831963 60951700 11/832629 11/832637 6097153510/407212 7252366 10/683064 10/683041 7275811 10/884889 10/92289010/922875 10/922885 10/922889 10/922884 10/922879 10/922887 10/92288810/922874 7234795 10/922871 10/922880 7293855 10/922882 10/92288310/922878 10/922872 10/922876 10/922886 10/922877 7147792 717577411/159193 11/491378 11766713 11/841647 11/482980 11/563684 11/48296711/482966 11/482988 11/482989 11/293832 11/293838 11/293825 11/29384111/293799 11/293796 11/293797 11/293798 11/124158 11/124196 11/12419911/124162 11/124202 11/124197 11/124154 11/124198 7284921 11/12415111/124160 11/124192 11/124175 11/124163 11/124149 11/124152 11/12417311/124155 7236271 11/124174 11/124194 11/124164 11/124200 11/12419511/124166 11/124150 11/124172 11/124165 11/124186 11/124185 11/12418411/124182 11/124201 11/124171 11/124181 11/124161 11/124156 11/12419111/124159 11/124176 11/124188 11/124170 11/124187 11/124189 11/12419011/124180 11/124193 11/124183 11/124178 11/124177 11/124148 11/12416811/124167 11/124179 11/124169 11/187976 11/188011 11/188014 11/48297911/735490 11/853018 11/944450 11/228540 11/228500 11/228501 11/22853011/228490 11/228531 11/228504 11/228533 11/228502 11/228507 11/22848211/228505 11/228497 11/228487 11/228529 11/228484 11/228489 11/22851811/228536 11/228496 11/228488 11/228506 11/228516 11/228526 11/22853911/228538 11/228524 11/228523 11/228519 11/228528 11/228527 11/22852511/228520 11/228498 11/228511 11/228522 11/228515 11/228537 11/22853411/228491 11/228499 11/228509 11/228492 11/228493 11/228510 11/22850811/228512 11/228514 11/228494 11/228495 11/228486 11/228481 11/22847711/228485 11/228483 11/228521 11/228517 11/228532 11/228513 11/22850311/228480 11/228535 11/228478 11/228479 6238115 6386535 6398344 66122406752549 6805049 6971313 6899480 6860664 6925935 6966636 7024995 72848526926455 7056038 6869172 7021843 6988845 6964533 6981809 7284822 725806711/155544 7222941 7284925 7278795 7249904 11/737726 11772240 11/86324611/863145 11/865650 6087638 6340222 6041600 6299300 6067797 62869356044646 6382769 6787051 6938990 11/242916 11/144799 11/198235 1186128211861284 11/766052 7152972 11/592996 D529952 6390605 6322195 66121106480089 6460778 6305788 6426014 6364453 6457795 6315399 6338548 70407366938992 6994425 6863379 6540319 6994421 6984019 7008043 6997544 63284316991310 10/965772 7140723 6328425 6982184 7267423 7134741 70665777152945 11/038200 7021744 6991320 7155911 11/107799 6595624 71529437125103 11/209709 7290857 7285437 7229151 11/330058 7237873 11/32916311/442180 11/450431 7213907 6417757 11/482951 11/545566 11/58382611/604315 11/604323 11/643845 11/706950 11/730399 11749121 11/75354911/834630 11/935389 11/869670 7095309 11/945157 11957473 119672356854825 6623106 6672707 6575561 6817700 6588885 7075677 6428139 65755496846692 6425971 7063993 6383833 6955414 6412908 6746105 6953236 64129047128388 6398343 6652071 6793323 6659590 6676245 7201460 6464332 66595936478406 6978613 6439693 6502306 6966111 6863369 6428142 6874868 63905916799828 6896358 7018016 10/296534 6328417 6322194 6382779 66297456565193 6609786 6609787 6439908 6684503 6843551 6764166 656161710/510092 6557970 6546628 10/510098 6652074 6820968 7175260 66821747303262 6648453 6834932 6682176 6998062 6767077 7278717 675550910/534813 6692108 10/534811 6672709 7303263 7086718 10/534881 667271010/534812 6669334 10/534804 7152958 7281782 6824246 7264336 666933310/534815 6820967 7306326 6736489 7264335 6719406 7222943 71884197168166 6974209 7086719 6974210 7195338 7252775 7101025 11/47428111/485258 11/706304 11/706324 11/706326 11/706321 11/772239 11/78259811/829941 11/852991 11852986 11/936062 11/934027 11955028 11/76344011/763442 11/246687 11/246718 11/246685 11/246686 11/246703 11/24669111/246711 11/246690 11/246712 11/246717 11/246709 11/246700 11/24670111/246702 11/246668 11/246697 11/246698 11/246699 11/246675 11/24667411/246667 11/829957 11/829960 11/829961 11/829962 11/829963 11/82996611/829967 11/829968 11/829969 11946839 11946838 11946837 119512307156508 7159972 7083271 7165834 7080894 7201469 7090336 715648910/760233 10/760246 7083257 7258422 7255423 7219980 10/760253 10/76025510/760209 7118192 10/760194 10/760238 7077505 7198354 7077504 10/7601897198355 10/760232 10/760231 7152959 7213906 7178901 7222938 71083537104629 11/446227 11/454904 11/472345 11/474273 7261401 11/47427911/482939 11/482950 11/499709 7306324 7306325 11/603824 11/60175611/601672 7303261 11/653253 11/706328 11/706299 11/706965 11/73708011/737041 11/778062 11/778566 11/782593 11/934018 11/945157 1195109511951828 11954906 11954949 11967226 7303930 11/246672 11/24667311/246683 11/246682 60/939086 11860538 11860539 11/860540 1186054111860542 11/936060 11877667 11877668 7246886 7128400 7108355 69913227287836 7118197 10/728784 10/728783 7077493 6962402 10/728803 714730810/728779 7118198 7168790 7172270 7229155 6830318 7195342 717526110/773183 7108356 7118202 10/773186 7134744 10/773185 7134743 71824397210768 10/773187 7134745 7156484 7118201 7111926 10/773184 701802111/060751 11/060805 11/188017 7128402 11/298774 11/329157 11/49004111/501767 7284839 7246885 7229156 11/505846 11/505857 7293858 11/52490811/524938 7258427 11/524912 7278716 11/592995 11/603825 11/64977311/650549 11/653237 11/706378 11/706962 11749118 11/754937 1174912011/744885 11/779850 11/765439 11/842950 11/839539 11/926121 11/09730811/097309 7246876 11/097299 11/097310 11/097213 11/210687 11/0972127147306 7261394 11/764806 11/782595 11965696 11/482953 11/48297711/544778 11/544779 11/764808 11/756624 11/756625 11/756626 11/75662711/756628 11/756629 11/756630 11/756631 7156289 7178718 722597911/712434 11/084796 11/084742 11/084806 09/575197 7079712 682594509/575165 6813039 7190474 6987506 6824044 7038797 6980318 68162747102772 09/575186 6681045 6678499 6679420 6963845 6976220 67280007110126 7173722 6976035 6813558 6766942 6965454 6995859 7088459 67209857286113 6922779 6978019 6847883 7131058 7295839 09/607843 09/6936906959298 6973450 7150404 6965882 7233924 09/575181 09/722174 71750797162259 6718061 10/291523 10/291471 7012710 6825956 10/291481 722209810/291825 7263508 7031010 6972864 6862105 7009738 6989911 698280710/291576 6829387 6714678 6644545 6609653 6651879 10/291555 729324010/291592 10/291542 7044363 7004390 6867880 7034953 6987581 721622410/291821 7162269 7162222 7290210 7293233 7293234 6850931 68655706847961 10/685523 10/685583 7162442 10/685584 7159784 10/80403410/793933 6889896 10/831232 7174056 6996274 7162088 10/943874 10/94387210/944044 7259884 10/944043 7167270 10/943877 6986459 10/954170 718144810/981626 10/981616 10/981627 7231293 7174329 10/992713 7295922 720059111/020106 11/020260 11/020321 11/020319 11/026045 11/059696 11/05103211/059674 11/107944 11/107941 11/082940 11/082815 11/082827 11/0828296991153 6991154 11/124256 11/123136 11/154676 11/159196 11/18200211/202251 11/202252 11/202253 11/203200 11/202218 11/206778 11/20342411/222977 11/228450 11/227239 11/286334 7225402 11/329187 11/34914311/491225 11/491121 11/442428 11/454902 11/442385 11/478590 727193111/520170 11/603057 11/706964 11/739032 11739014 11/834633 11/83084811/830849 11/839542 11/866394 11/934077 11951874 7068382 7007851 69579216457883 10/743671 7044381 11/203205 7094910 7091344 7122685 70380667099019 7062651 6789194 6789191 10/900129 7278018 10/913350 10/98297510/983029 11/331109 6644642 6502614 6622999 6669385 6827116 701112810/949307 6549935 6987573 6727996 6591884 6439706 6760119 72953327064851 6826547 6290349 6428155 6785016 6831682 6741871 6927871 69803066965439 6840606 7036918 6977746 6970264 7068389 7093991 719049110/901154 10/932044 10/962412 7177054 10/962552 10/965733 10/96593310/974742 10/982974 7180609 10/986375 11/107817 7292363 11/14916011/206756 11/250465 7202959 11/653219 11/706309 11/730389 11/73039260/953443 11/866387 60974077 6982798 6870966 6822639 6474888 66278706724374 6788982 7263270 6788293 6946672 6737591 7091960 09/6935146792165 7105753 6795593 6980704 6768821 7132612 7041916 6797895 70159017289882 7148644 10/778056 10/778058 10/778060 10/778059 10/77806310/778062 10/778061 10/778057 7096199 7286887 10/917467 10/91746610/917465 7218978 7245294 7277085 7187370 10/917436 10/943856 10/9193797019319 10/943878 10/943849 7043096 7148499 11/144840 11/15555611/155557 11/193481 11/193435 11/193482 11/193479 11/255941 11/28167111/298474 7245760 11/488832 11/495814 11/495823 11/495822 11/49582111/495820 11/653242 11/754370 60911260 11/829936 11/839494 1186630511866313 11866324 11866336 11866348 11866359 11970951 7055739 72333206830196 6832717 7182247 7120853 7082562 6843420 10/291718 67897317057608 6766944 6766945 7289103 10/291559 7299969 7264173 10/4098647108192 10/537159 7111791 7077333 6983878 10/786631 7134598 10/8933726929186 6994264 7017826 7014123 7134601 7150396 10/971146 70178237025276 7284701 7080780 11/074802 11/442366 11749158 11/842948 10/49216910/492152 10/492168 10/492161 7308148 10/502575 10/531229 10/68315110/531733 10/683040 10/510391 10/919260 10/510392 10/778090 11/94440411/936638 6957768 09/575172 7170499 7106888 7123239 6982701 69827037227527 6786397 6947027 6975299 7139431 7048178 7118025 6839053 70159007010147 7133557 6914593 10/291546 6938826 7278566 7123245 69926627190346 11/074800 11/074782 11/074777 11/075917 7221781 11/1028437213756 11/188016 7180507 7263225 7287688 11/737094 11/753570 11/78259611/865711 11856061 11856062 11856064 11856066 11/672522 11/67295011/672947 11/672891 11/672954 11/672533 11754310 11/754321 11/75432011/754319 11/754318 11/754317 11/754316 11/754315 11/754314 11/75431311/754312 11/754311 6593166 7132679 6940088 7119357 7307272 67555136974204 6409323 7055930 6281912 6893109 6604810 6824242 6318920 72108676488422 6655786 6457810 6485135 6796731 6904678 6641253 7125106 67866587097273 6824245 7222947 6918649 6860581 6929351 7063404 6969150 70046526871938 6905194 6846059 6997626 10/974881 7029098 6966625 71147947207646 7077496 7284831 11/072529 7152938 7182434 7182430 11/1028427032993 11/155513 11/155545 11/144813 7172266 7258430 7128392 721086611/488066 11/505933 11/540727 11/635480 11/707946 11/706303 11/70908411/730776 11/744143 11/779845 11/782589 11/863256 11/940302 11/94023511955359 11/066161 11/066160 11/066159 11/066158 7287831 11/8759366804030 6807315 6771811 6683996 7271936 7304771 6965691 7058219 72896817187807 7181063 11/338783 11/603823 11/650536 10/727181 10/72716210/727163 10/727245 7121639 7165824 7152942 10/727157 7181572 70961377302592 7278034 7188282 10/727159 10/727180 10/727179 10/72719210/727274 10/727164 10/727161 10/727198 10/727158 10/754536 10/75493810/727227 10/727160 10/934720 7171323 7278697 11/442131 11/47427811/488853 11/488841 11749750 11749749 11955127 11951213 10/2965226795215 7070098 7154638 6805419 6859289 6977751 6398332 6394573 66229236747760 6921144 10/884881 7092112 7192106 11/039866 7173739 69865607008033 11/148237 7222780 7270391 7150510 11/478599 11/499749 11/52138811/738518 11/482981 11/743662 11/743661 11/743659 11/743655 11/74365711/752900 11926109 11927163 11929567 7195328 7182422 11/650537 11/71254010/854521 10/854522 10/854488 7281330 10/854503 10/854504 10/8545097188928 7093989 10/854497 10/854495 10/854498 10/854511 10/85451210/854525 10/854526 10/854516 7252353 10/854515 7267417 10/85450510/854493 7275805 7314261 10/854490 7281777 7290852 10/854528 10/85452310/854527 10/854524 10/854520 10/854514 10/854519 10/854513 10/85449910/854501 7266661 7243193 10/854518 10/854517 10/934628 716334511/499803 11/601757 11/706295 11/735881 11748483 11749123 11/76606111775135 11772235 11/778569 11/829942 11/870342 11/935274 11/93723911961907 11961940 11961961 11/014731 D529081 D541848 D528597 69249076712452 6416160 6238043 6958826 6812972 6553459 6967741 6956669 69037666804026 7259889 6975429 10/636234 10/636233 7301567 10/636216 72744857139084 7173735 7068394 7286182 7086644 7250977 7146281 7023567 71361837083254 6796651 7061643 7057758 6894810 6995871 7085010 7092126 71233827061650 10/853143 6986573 6974212 7307756 7173737 10/954168 724686811/065357 7137699 11/107798 7148994 7077497 11/176372 7248376 11/22515811/225154 7173729 11/442132 11/478607 11/503085 11/545502 11/58394311/585946 11/653239 11/653238 11/764781 11/764782 11/779884 1184566611/872637 11/944401 11/940215 11/544764 11/544765 11/544772 11/54477311/544774 11/544775 11/544776 11/544766 11/544767 11/544771 11/54477011/544769 11/544777 11/544768 11/544763 11/293804 11/293840 11/29380311/293833 11/293834 11/293835 11/293836 11/293837 11/293792 11/29379411/293839 11/293826 11/293829 11/293830 11/293827 11/293828 727049411/293823 11/293824 11/293831 11/293815 11/293819 11/293818 11/29381711/293816 11/838875 11/482978 11/640356 11/640357 11/640358 11/64035911/640360 11/640355 11/679786 11/872714 10/760254 10/760210 10/7602027201468 10/760198 10/760249 7234802 7303255 7287846 7156511 10/7602647258432 7097291 10/760222 10/760248 7083273 10/760192 10/76020310/760204 10/760205 10/760206 10/760267 10/760270 7198352 10/7602717303251 7201470 7121655 7293861 7232208 10/760186 10/760261 70832727261400 11/474272 11/474315 7311387 11/583874 7303258 11/70632211/706968 11/749119 11749157 11779848 11/782590 11/855152 1185515111/870327 11/934780 11/935992 11951193 11/014764 11/014763 11/01474811/014747 11/014761 11/014760 11/014757 7303252 7249822 11/01476211/014724 11/014723 11/014756 11/014736 11/014759 11/014758 11/01472511/014739 11/014738 11/014737 11/014726 11/014745 11/014712 72704057303268 11/014735 11/014734 11/014719 11/014750 11/014749 724983311/758640 11/775143 11/838877 11944453 11/944633 11955065 11/01476911/014729 11/014743 11/014733 7300140 11/014755 11/014765 11/01476611/014740 7284816 7284845 7255430 11/014744 11/014741 11/01476811/014767 11/014718 11/014717 11/014716 11/014732 11/014742 11/09726811/097185 11/097184 11/778567 11852958 11852907 11/872038 1195509311961578 11/293820 11/293813 11/293822 11/293812 11/293821 11/29381411/293793 11/293842 11/293811 11/293807 11/293806 11/293805 11/29381011/688863 11/688864 11/688865 11/688866 11/688867 11/688868 11/68886911/688871 11/688872 11/688873 11/741766 11/482982 11/482983 11/48298411/495818 11/495819 11/677049 11/677050 11/677051 11872719 1187271811/014722 11/934781 D528156 10/760180 7111935 10/760213 10/76021910/760237 7261482 10/760220 7002664 10/760252 10/760265 708842011/446233 11/503083 11/503081 11/516487 11/599312 6364451 65333906454378 7224478 6559969 6896362 7057760 6982799 11/202107 11/74367211744126 11/743673 7093494 7143652 7089797 7159467 7234357 71246437121145 7089790 7194901 6968744 7089798 7240560 7137302 11/4421777171855 7260995 7260993 7165460 7222538 7258019 11/543047 725802011/604324 11/642520 11/706305 11/707056 11744211 11/767526 11/77984611/764227 11/829943 11/829944 6454482 6808330 6527365 6474773 65509977093923 6957923 7131724 10/949288 7168867 7125098 11/706966 11/1857227249901 7188930 11/014728 11/014727 D536031 D531214 7237888 71686547201272 6991098 7217051 6944970 10/760215 7108434 10/760257 72104077186042 10/760266 6920704 7217049 10/760214 10/760260 7147102 72878287249838 10/760241 10/962413 10/962427 7261477 7225739 10/96240210/962425 10/962428 7191978 10/962426 10/962409 10/962417 10/9624037163287 7258415 10/962523 7258424 10/962410 7195412 7207670 72704017220072 11/474267 11/544547 11/585925 11/593000 11/706298 11/70629611/706327 11/730760 11/730407 11/730787 11/735977 11/736527 11/75356611/754359 11/778061 11/765398 11/778556 11/829937 11/780470 11/86639911/223262 11/223018 11/223114 11955366 11/223022 11/223021 11/22302011/223019 11/014730 D541849 29/279123 6716666 6949217 6750083 70144516777259 6923524 6557978 6991207 6766998 6967354 6759723 687025910/853270 6925875 10/898214 7095109 7145696 10/976081 7193482 71347397222939 7164501 7118186 7201523 7226159 7249839 7108343 7154626 707929210/980184 7233421 7063408 10/983082 10/982804 7032996 10/98283410/982833 10/982817 7217046 6948870 7195336 7070257 10/986813 10/9867857093922 6988789 10/986788 7246871 10/992748 10/992747 7187468 10/9928287196814 10/992754 7268911 7265869 7128384 7164505 7284805 70254347298519 7280244 7206098 7265877 7193743 7168777 11/006734 71953297198346 7281786 11/013363 11/013881 6959983 7128386 7097104 11/0136367083261 7070258 7083275 7110139 6994419 6935725 11/026046 71788927219429 6988784 11/026135 7289156 11/064005 7284976 7178903 72732747083256 11/064008 7278707 11/064013 6974206 11/064004 7066588 722294011/075918 7018025 7221867 7290863 7188938 7021742 7083262 719211911/083021 7036912 7175256 7182441 7083258 7114796 7147302 11/0847577219982 7118195 7229153 6991318 7108346 11/248429 11/239031 71788997066579 11/281419 11/298633 11/329188 11/329140 7270397 7258425 72378747152961 11/478592 7207658 11/484744 7311257 7207659 11/525857 11/54056911/583869 11/592985 11/585947 7306307 11/604316 11/604309 11/60430311/643844 11/650553 11/655940 11/653320 7278713 11/706381 11/70632311/706963 11/713660 7290853 11/696186 11/730390 11/737139 11/73774911/740273 11749122 11/754361 11766043 11/764775 11/768872 11/77515611/779271 11/779272 11/829938 11/839502 11858852 11/862188 1185979011/872618 11/923651 11950255 11930001 11955362 11965718 6485123 64256576488358 7021746 6712986 6981757 6505912 6439694 6364461 6378990 64256586488361 6814429 6471336 6457813 6540331 6454396 6464325 6443559 64356646412914 6488360 6550896 6439695 6447100 09/900160 6488359 663787310/485738 6618117 10/485737 6803989 7234801 7044589 7163273 64161546547364 10/485744 6644771 7152939 6565181 10/485805 6857719 72554146702417 7284843 6918654 7070265 6616271 6652078 6503408 6607263 71119246623108 6698867 6488362 6625874 6921153 7198356 6536874 6425651 643566710/509997 6527374 10/510154 6582059 10/510152 6513908 7246883 65403326547368 7070256 6508546 10/510151 6679584 10/510000 6857724 10/5099986652052 10/509999 6672706 10/510096 6688719 6712924 6588886 70775087207654 6935724 6927786 6988787 6899415 6672708 6644767 6874866 68303166994420 6954254 7086720 7240992 7267424 7128397 7084951 7156496 70665787101023 11/165027 11/202235 11/225157 7159965 7255424 11/349519 71376867201472 7287829 11/504602 7216957 11/520572 11/583858 11/58389511/585976 11/635488 7278712 11/706952 11/706307 7287827 1194445111/740287 11/754367 11/758643 11/778572 11859791 11/863260 11/87417811/936064 11951983 6916082 6786570 10/753478 6848780 6966633 71793956969153 6979075 7132056 6832828 6860590 6905620 6786574 6824252 70972826997545 6971734 6918652 6978990 6863105 10/780624 7194629 10/7917926890059 6988785 6830315 7246881 7125102 7028474 7066575 6986202 70445847210762 7032992 7140720 7207656 7285170 11/048748 7008041 70113907048868 7014785 7131717 7284826 11/176158 7182436 7104631 72409937290859 11/202217 7172265 7284837 7066573 11/298635 7152949 11/44216111/442133 11/442126 7156492 11/478588 11/505848 7287834 11/52586111/583939 11/545504 7284326 11/635485 11/730391 11/730788 11/74914811/749149 11/749152 11/749151 11/759886 11/865668 11/874168 11/87420311965722 6824257 7270475 6971811 6878564 6921145 6890052 7021747 69293456811242 6916087 6905195 6899416 6883906 6955428 7284834 6932459 69624107033008 6962409 7013641 7204580 7032997 6998278 7004563 6910755 69691426938994 7188935 10/959049 7134740 6997537 7004567 6916091 70775886918707 6923583 6953295 6921221 7001008 7168167 7210759 11/00811511/011120 11/012329 6988790 7192120 7168789 7004577 7052120 11/1230076994426 7258418 7014298 11/124348 11/177394 7152955 7097292 72076577152944 7147303 11/209712 7134608 7264333 7093921 7077590 714729711/239029 11/248832 11/248428 11/248434 7077507 7172672 7175776 70867177101020 11/329155 7201466 11/330057 7152967 7182431 7210666 72523677287837 11/485255 11/525860 6945630 7018294 6910014 6659447 66483217082980 6672584 7073551 6830395 7289727 7001011 6880922 6886915 66447876641255 7066580 6652082 7284833 6666544 6666543 6669332 6984023 67331046644793 6723575 6953235 6663225 7076872 7059706 7185971 7090335 68548276793974 10/636258 7222929 6739701 7073881 7155823 7219427 70085036783216 6883890 6857726 10/636274 6641256 6808253 6827428 68025876997534 6959982 6959981 6886917 6969473 6827425 7007859 6802594 67927546860107 6786043 6863378 7052114 7001007 10/729151 10/729157 69487946805435 6733116 10/683006 7008046 6880918 7066574 6983595 69235277275800 7163276 7156495 6976751 6994430 7014296 7059704 7160743 71757757287839 7097283 7140722 11/123009 11/123008 7080893 7093920 72704927128093 7052113 7055934 11/155627 7278796 11/159197 7083263 71455927025436 11/281444 7258421 11/478591 11/478735 7226147 11/482940 719533911/503061 11/505938 7284838 7293856 11/544577 11/540576 11/58596411/592991 11/599342 11/600803 11/604321 11/604302 11/635535 11/63548611/643842 11/655987 11/650541 11/706301 11/707039 11/730388 11/73078611/730785 11/739080 11/764746 11/768875 11/779847 11/829940 1184724011/834625 11/863210 11/865680 11/874156 11/923602 11951940 1195498811961662 7067067 6776476 6880914 7086709 6783217 7147791 6929352 71440956820974 6918647 6984016 7192125 6824251 6834939 6840600 6786573 71445196799835 6959975 6959974 7021740 6935718 6938983 6938991 7226145 71407196988788 7022250 6929350 7011393 7004566 7175097 6948799 7143944 73101577029100 6957811 7073724 7055933 7077490 7055940 10/991402 72346457032999 7066576 7229150 7086728 7246879 7284825 7140718 7284817 71440987044577 7284824 7284827 7189334 7055935 7152860 11/203188 11/20317311/202343 7213989 11/225156 11/225173 7300141 7114868 7168796 715996711/272425 7152805 11/298530 11/330061 7133799 11/330054 11/3292847152956 7128399 7147305 7287702 11/442160 7246884 7152960 11/44212511/454901 11/442134 11/450441 11/474274 11/499741 7270399 68577286857729 6857730 6989292 7126216 6977189 6982189 7173332 7026176 69795996812062 6886751 10/804057 10/804036 7001793 6866369 6946743 10/8040486886918 7059720 10/846561 10/846562 10/846647 10/846649 10/8466276951390 6981765 6789881 6802592 7029097 6799836 7048352 7182267 70252796857571 6817539 6830198 6992791 7038809 6980323 7148992 7139091 69471737101034 6969144 6942319 6827427 6984021 6984022 6869167 6918542 70078526899420 6918665 6997625 6988840 6984080 6845978 6848687 6840512 68633657204582 6921150 7128396 6913347 7008819 6935736 6991317 7284836 70559477093928 7100834 7270396 7187086 7290856 7032825 7086721 7159968 70104567147307 7111925 11/144812 7229154 11/505849 11/520570 11/52057511/546437 11/540575 11/583937 7278711 7290720 11/592207 11/63548911/604319 11/635490 11/635525 7287706 11/706366 11/706310 11/70630811/785108 11/744214 11744218 11748485 11/748490 11/764778 11/76602511/834635 11839541 11860420 11/865693 11/863118 11/866307 11/86634011/869684 11/869722 11/869694 11/876592 11/945244 11951121 11/94523811955358 11965710 11962050

BACKGROUND

The Applicant has previously described a method of enabling users toaccess information from a computer system via a printed substrate e.g.paper. The substrate has coded data printed thereon, which is read by anoptical sensing device when the user interacts with the substrate usingthe sensing device. A computer receives interaction data from thesensing device and uses this data to determine what action is beingrequested by the user. For example, a user may make handwritten inputonto a form or make a selection gesture around a printed item. Thisinput is interpreted by the computer system with reference to a pagedescription corresponding to the printed substrate.

It would be desirable to provide a broader range of functionalitiesavailable to the user via the sensing device. It would be particularlydesirable to provide this broader range of functionalities withoutintroducing a plethora of separate functional systems into the sensingdevice.

SUMMARY OF INVENTION

In a first aspect the present invention provides a system forcontrolling movement of a cursor on a display device, the systemcomprising:

-   -   a substrate having a position-coding pattern disposed on or in a        surface thereof;    -   a sensing device comprising:        -   an image sensor for optically imaging the position-coding            pattern; and        -   a processor configured for:            -   generating absolute motion data by determining a                plurality of absolute positions of the sensing device                relative to the surface using the imaged position-coding                pattern;            -   generating orientation data indicative of an orientation                of the sensing device relative to the substrate; and            -   using the orientation data to translate the absolute                motion data into relative motion data, said relative                motion data being indicative of relative motion of the                sensing device from the perspective of a user; and        -   communication means for communicating the relative motion            data to a computer system; and    -   the computer system configured for:        -   receiving said relative motion data from the sensing device;        -   interpreting said relative motion data as cursor movement;            and        -   generating cursor control commands for said display device.

Optionally, the relative motion data is indicative of relative positionchanges of the sensing device substantially from a perspective of auser, and irrespective of an orientation of said substrate.

Optionally, the position-coding pattern comprises a plurality of tags,each tag identifying a location on the surface and a rotationalorientation of the tag relative to the substrate, thereby enabling a yawof the sensing device relative to the substrate to be determined.

Optionally, said display device is selected from at least one of:

-   -   a display device associated with the computer system    -   a display device integral with the computer system; and    -   a display device remote from the computer system.

Optionally, said sensing device is operable in a plurality of modes,said plurality including a cursor mode and at least one other mode, andwherein the computer system is further configured for:

-   -   determining that said sensing device is operating in a cursor        mode.

Optionally, said at least one other mode is selected from the groupcomprising: a scroll mode; a hyperlinking mode; a searching mode; acontent-extraction mode; and a handwriting mode.

Optionally, said sensing device comprises a mode selector, and saidinteraction data comprises mode data indicative of said cursor mode.

Optionally, said mode selector comprises at least one of:

-   -   one or more mode buttons operable by a user; and    -   a sensor for detecting a force exerted by said sensing device on        said surface.

Optionally, said computer system is configured for retrieving storedmode data indicative of a most recent mode selected for said sensingdevice.

Optionally, said computer system is further configured for:

-   -   determining if said sensing device is positioned within a cursor        zone of said substrate, said cursor zone being activated by        determination of said cursor mode; and    -   interpreting relative motion of said sensing device only within        said cursor zone as said cursor movement.

Optionally, said computer system is further configured for:

-   -   determining if said sensing device is positioned within a scroll        zone of said substrate, said scroll zone being activated by        determination of said cursor mode; and    -   interpreting the interaction of said sensing device within said        scroll zone as a scroll action;    -   scrolling a page displayed on said display device according to        said scroll action.

Optionally, said computer system is configured for at least one of:

-   -   interpreting at least one absolute position of said sensing        device within said scroll zone to be indicative of a scroll        direction; and    -   interpreting relative motion of said sensing device within said        scroll zone to be indicative of a scroll direction.

Optionally, the position-coding pattern is further indicative of anidentity of the substrate and the interaction data comprises substrateidentity data.

Optionally, the substrate is a cursor control substrate and saidcomputer system is configured for using the substrate identity data toretrieve a cursor page description corresponding to said cursor controlsubstrate, said cursor page description comprising a cursor zone withinwhich the interaction of said sensing device is interpreted as saidcursor movement.

Optionally, said cursor page description comprises a scroll zone withinwhich the interaction of said sensing device is interpreted as a scrollaction, and wherein said computer system is configured to scroll a pagedisplayed on said display device according to said scroll action.

Optionally, said cursor control substrate has visible markingsindicating at least one of: said cursor zone, said scroll zone and ascroll direction.

Optionally, said scroll zone is located at an edge region of saidsubstrate.

In a further aspect the present invention provides a method ofcontrolling movement of a cursor on a display device via a substratehaving a position-coding pattern disposed on or in a surface thereof,said method comprising the steps of:

-   -   receiving, in a computer system, interaction data indicative of        an interaction of the sensing device with the substrate, said        interaction data comprising:        -   absolute motion data indicative of a plurality of absolute            positions of the sensing device relative to the surface; and        -   orientation data indicative of an orientation of the sensing            device relative to the substrate; and    -   using the orientation data to translate the absolute motion data        into relative motion data, said relative motion data being        indicative of position changes of the sensing device relative to        itself;    -   interpreting said relative motion data as cursor movement; and    -   generating cursor control commands for said display device.

In another aspect the present invention provides a sensing device forcontrolling movement of a cursor on a display device, said sensingdevice comprising:

-   -   an image sensor for optically imaging a position-coding pattern        disposed on or in a surface; and    -   a processor configured for:        -   generating absolute motion data by determining a plurality            of absolute positions of the sensing device relative to the            surface using the imaged position-coding pattern;        -   generating orientation data indicative of an orientation of            the sensing device relative to the substrate; and        -   using the orientation data to translate the absolute motion            data into relative motion data, said relative motion data            being indicative of relative motion of the sensing device            from the perspective of a user; and    -   communication means for communicating the relative motion data        to a computer system, thereby enabling the computer system to        generate cursor control commands using the relative motion data        for controlling movement of the cursor on the display device.

In a another aspect the present invention provides a computer system forcontrolling movement of a cursor on a display device via a substratehaving a position-coding pattern disposed on or in a surface thereof,said computer system being configured for:

-   -   receiving interaction data indicative of an interaction of the        sensing device with the substrate, said interaction data        comprising:        -   absolute motion data indicative of a plurality of absolute            positions of the sensing device relative to the surface; and        -   orientation data indicative of an orientation of the sensing            device relative to the substrate;    -   using the orientation data to translate the absolute motion data        into relative motion data, said relative motion data being        indicative of position changes of the sensing device relative to        itself;    -   interpreting said relative motion data as cursor movement; and    -   generating cursor control commands for said display device.

In a second aspect the present invention provides a sensing device forinteraction with a surface, said sensing device having automatic modeselection, said sensing device comprising:

-   -   an image sensor for imaging the surface and generating image        data;    -   a motion sensor configured for determining one or more relative        position changes of the sensing device;    -   a processor configured for:        -   receiving the image data; and        -   automatically selecting, using said image data, either an            interaction mode or a cursor mode for said sensing device;            and    -   communication means for transmitting either interaction data or        cursor data to a computer system, dependent on said selected        mode,        wherein said processor is configured to:    -   select the interaction mode and generate interaction data from        the image data if said image data indicates that said sensing        device is interacting with a first surface having a        position-coding pattern disposed thereon, said interaction data        being indicative of at least one absolute location of the        sensing device relative to the surface; and    -   select the cursor mode if said image data indicates that said        sensing device is interacting with a second surface lacking a        position-coding pattern, said cursor data being indicative of        said one or more relative position changes of the sensing        device.

Optionally, the motion sensor is selected from any one of the groupcomprising: at least one accelerometer; a mechanical mouse; an opticalmouse; and a point interferometry device.

Optionally, said motion sensor is an optical mouse utilizing at leastone of: a pattern-based optical mouse technique; a texture-based opticalmouse technique; and a laser-speckle-based mouse technique.

Optionally, the position-coding pattern of the first surface isindicative of a plurality of locations on the surface and of an identityof a region.

Optionally, in said interaction mode, said processor is configured fordetermining the identity of the region using the imaged position-codingpattern, and said interaction data is further indicative of the identityof the region.

Optionally, the identity of the region is coincident with an identity ofthe surface.

Optionally, the position-coding pattern is comprised of a plurality oftags, each tag identifying the identity of the surface and a location ofthe tag on the surface.

In a further aspect the present invention provides a system forinitiating an action corresponding to interaction of a sensing devicerelative to a surface, said system comprising:

(A) the sensing device comprising:

-   -   an image sensor for imaging the surface and generating image        data;    -   a motion sensor configured for determining one or more relative        position changes of the sensing device;    -   a processor configured for:        -   receiving the image data; and        -   automatically selecting, using said image data, either an            interaction mode or a cursor mode for said sensing device;            and    -   communication means for transmitting either interaction data or        cursor data to a computer system, dependent on said selected        mode,        wherein said processor is configured to:    -   select the interaction mode and generate interaction data if        said image data indicates that said sensing device is        interacting with a first surface having a position-coding        pattern disposed thereon, said interaction data being indicative        of an absolute location of the sensing device relative to the        surface; and    -   select the cursor mode if said image data indicates that said        sensing device is interacting with a second surface lacking a        position-coding pattern, said cursor data being indicative of        said one or more relative position changes of the sensing        device; and        (B) the computer system configured for:    -   receiving the interaction data and the cursor data from the        sensing device;    -   interpreting said interaction data to initiate an action        corresponding to said interaction with said surface; and    -   interpreting said cursor data to control movement of a cursor on        a display device.

Optionally, said action initiated by said interaction data is selectedfrom at least one of: hyperlinking; form-filling; searching; andcontent-extraction.

Optionally, the position-coding pattern of the first surface isindicative of a plurality of locations on the surface and of an identityof a region.

Optionally, in said interaction mode, said processor is configured fordetermining the identity of the region using the imaged position-codingpattern, and said interaction data is further indicative of the identityof the region.

Optionally, said computer system is configured to interpret saidinteraction data by the steps of:

-   -   identifying and retrieving a page description corresponding to        the first surface using the identity of the region;    -   determining a request using the retrieved page description and        the interaction data; and    -   initiating an action based on said request.

Optionally, the identity of the region is coincident with an identity ofthe surface.

Optionally, the position-coding pattern is comprised of a plurality oftags, each tag identifying the identity of the surface and a location ofthe tag on the surface.

Optionally, display device is selected from at least one of:

-   -   a display device associated with the computer system    -   a display device integral with the computer system; and    -   a display device remote from the computer system.

In a further aspect the present invention provides a method ofautomatically selecting a mode of a sensing device interacting with asurface, said sensing device comprising a motion sensor configured fordetermining one or more relative position changes of the sensing device,said method comprising the steps of:

-   -   imaging the surface and generating image data;    -   automatically selecting, using said image data, either an        interaction mode or a cursor mode for said sensing device; and    -   transmitting either interaction data or cursor data to a        computer system, dependent on said selected mode,        wherein:    -   the interaction mode is selected and the interaction data is        generated from the image data if said image data indicates that        said sensing device is interacting with a first surface having a        position-coding pattern disposed thereon, said interaction data        being indicative of at least one absolute location of the        sensing device relative to the surface; and    -   the cursor mode is selected and one or more relative position        changes of the sensing device are determined if said image data        indicates that said sensing device is interacting with a second        surface lacking a position-coding pattern, said cursor data        being indicative of said one or more relative position changes        of the sensing device.

In a further aspect the method further comprising the steps of:

-   -   receiving the interaction data in the computer system; and    -   interpreting said interaction data to initiate an action        corresponding to said interaction with said surface.

In another aspect the method further comprising the steps of:

-   -   receiving the cursor data from the sensing device;    -   interpreting said cursor data to control movement of a cursor on        a display device.

In a third aspect the present invention provides a system for enablingscrolling of a page displayed on a display device, the systemcomprising:

-   -   a substrate having a position-coding pattern disposed on or in a        surface thereof;    -   a sensing device operable in a plurality of modes including a        cursor mode, said sensing device comprising:        -   an image sensor for optically imaging the position-coding            pattern; and        -   a processor configured for generating interaction data            indicative of an interaction of the sensing device with the            surface, said interaction data being indicative of a            position or movement of the sensing device relative to the            surface;        -   communication means for communicating the interaction data            to a computer system; and    -   the computer system configured for:        -   receiving the interaction data from the sensing device;        -   determining that said sensing device is operating in a            cursor mode;        -   determining a scroll zone for said substrate;        -   determining if said sensing device is positioned within said            scroll zone;        -   interpreting said position or movement of said sensing            device within said scroll zone as a scrolling action; and        -   generating a scroll control command for said display device            so as to scroll said displayed page.

Optionally, the sensing device is operable in two or more modes selectedfrom the group comprising: said cursor mode; a hyperlinking mode; asearching mode; a content-extraction mode; and a handwriting mode.

Optionally, said sensing device comprises a mode selector, and saidinteraction data comprises mode data indicative of said cursor mode.

Optionally, said mode selector comprises at least one of:

-   -   one or more mode buttons operable by a user; and    -   a sensor for detecting a force exerted by said sensing device on        said surface.

Optionally, said computer system is configured for retrieving storedmode data indicative of a most recent mode selected for said sensingdevice.

Optionally, said computer system is configured for at least one of:

-   -   interpreting at least one absolute position of said sensing        device within said scroll zone to be indicative of a scroll        direction; and    -   interpreting movement of said sensing device within said scroll        zone to be indicative of a scroll direction.

Optionally, said scroll direction is selected from at least one of:

-   -   vertical scrolling;    -   horizontal scrolling; and    -   diagonal scrolling.

Optionally, said scroll zone is located at an edge region of saidsubstrate.

Optionally, said substrate comprises a plurality of scroll zones.

Optionally, said substrate comprises visible markings indicating atleast one of: said scroll zone and a scroll direction.

Optionally, said computer system is further configured for:

-   -   determining if said sensing device is positioned within a cursor        zone of said substrate;    -   interpreting movement of said sensing device as a cursor        movement; and    -   generating cursor control commands for said display device.

Optionally, said display device is selected from at least one of:

-   -   a display device associated with the computer system    -   a display device integral with the computer system; and    -   a display device remote from the computer system.

In a further aspect the system further comprising the display device.

Optionally, the position-coding pattern is further indicative of anidentity of the substrate and the interaction data comprises substrateidentity data.

Optionally, said computer system is configured for retrieving a pagedescription corresponding to said substrate using said substrateidentity.

Optionally, said computer is configured for retrieving said pagedescription if it is determined that said sensing device is notoperating in said cursor mode.

Optionally, said computer system is configured for:

-   -   using said position or movement of said sensing device together        with said retrieved page description to interpret said        interaction of said sensing device with said substrate; and    -   initiate an action corresponding to said interaction.

In another aspect the present invention provides a method of enablingscrolling of a page displayed on a display device via a substrate havingposition-coding pattern disposed in or on a surface thereof, said methodcomprising, in a computer system, the steps of:

-   -   receiving interaction data indicative of an interaction of the        sensing device with the substrate, said interaction data being        indicative of a position or movement of the sensing device        relative to the surface;    -   determining that said sensing device is operating in a cursor        mode;    -   determining a scroll zone for said substrate;    -   determining if said sensing device is positioned within a scroll        zone of said substrate;    -   interpreting said position or movement of said sensing device        within said scroll zone as a scrolling action; and    -   generating a scroll control command for said display device so        as to scroll said displayed page.

In a further aspect the present invention provides a computer system forcontrolling scrolling of a page displayed on a display device, saidcomputer system being configured for:

-   -   receiving interaction data indicative of an interaction of the        sensing device with a substrate having a position-coding pattern        disposed on or in a surface thereof, said interaction data being        indicative of a position or movement of the sensing device        relative to the surface;    -   determining that said sensing device is operating in a cursor        mode;    -   determining a scroll zone for said substrate;    -   determining if said sensing device is positioned within a scroll        zone of said substrate;    -   interpreting said position or movement of said sensing device        within said scroll zone as a scrolling action; and    -   generating a scroll control command for said display device so        as to scroll said displayed page.

In a fourth aspect the present invention provides a system for enablinguser input and control of a cursor on a display device, the systemcomprising:

-   -   a substrate having a position-coding pattern disposed on or in a        surface thereof, said substrate having at least one input        element and a discrete cursor zone;    -   a sensing device comprising:        -   an image sensor for optically imaging the position-coding            pattern; and        -   a processor configured for generating interaction data            indicative of an interaction of the sensing device with the            surface, said interaction data being indicative of a            position or movement of the sensing device relative to the            surface;        -   communication means for communicating the interaction data            to a computer system; and    -   the computer system configured for:        -   receiving the interaction data from the sensing device;        -   retrieving a page description corresponding to said            substrate;        -   determining whether said sensing device is positioned within            said cursor zone;        -   interpreting movement of said sensing device within said            cursor zone as a cursor movement and generating            corresponding cursor control commands for said display            device; and        -   otherwise determining if said position or movement of said            sensing device is within a zone of said at least one input            element and initiating an action corresponding to said at            least one input element.

Optionally, said at least one user input element is a GUI control buttonand said action is a corresponding GUI control action.

Optionally, said GUI control action is selected from the groupcomprising: scrolling; web browser control; page up; page down; cut;copy; paste; tab between GUI applications; launching of a GUIapplication; volume control; log off; sleep; and keyboard input.

Optionally, said substrate is an explicitly dedicated GUI controlsubstrate, said substrate comprising visible markings indicating saidcursor zone and said at least one GUI control button.

Optionally, said at least one input element is a hyperlink element, andsaid action is hyperlinking.

Optionally, said substrate comprises a scroll zone, and said computersystem is configured for interpreting a position or movement of saidsensing device within said scroll zone to be indicative of a scrollingaction.

Optionally, said computer system is configured for at least one of:

-   -   interpreting at least one absolute position of said sensing        device within said scroll zone to be indicative of a scroll        direction; and    -   interpreting movement of said sensing device within said scroll        zone to be indicative of a scroll direction.

Optionally, said scroll direction is selected from at least one of:

-   -   vertical scrolling;    -   horizontal scrolling; and    -   diagonal scrolling.

Optionally, said substrate comprises a plurality of scroll zones.

Optionally, said substrate comprises visible markings indicating atleast one of: said scroll zone and a scroll direction.

Optionally, said computer system is configured for interpreting movementof said sensing device within said cursor zone as relative movement.

Optionally, said computer system is configured for interpreting theposition or movement of said sensing device outside said cursor zone asan absolute position or movement relative to the surface.

Optionally, said display device is selected from at least one of:

-   -   a display device associated with the computer system    -   a display device integral with the computer system; and    -   a display device remote from the computer system.

In a further aspect the system further comprising the display device.

Optionally, the position-coding pattern is further indicative of anidentity of the substrate and the interaction data comprises substrateidentity data.

Optionally, said computer system is configured for retrieving the pagedescription corresponding to said substrate using said substrateidentity.

In another aspect the present invention provides a method of enablinguser input and control of a cursor on a display device via a substratehaving position-coding pattern disposed in or on a surface thereof, saidsubstrate having at least one input element and a discrete cursor zone,said method comprising, in a computer system, the steps of:

-   -   receiving interaction data indicative of an interaction of the        sensing device with the substrate, said interaction data being        indicative of a position or movement of the sensing device        relative to the surface;    -   retrieving a page description corresponding to said substrate;    -   determining whether said sensing device is positioned within        said cursor zone;    -   interpreting movement of said sensing device within said cursor        zone as a cursor movement and generating corresponding cursor        control commands for said display device; and    -   otherwise determining if said position or movement of said        sensing device is within a zone of said at least one input        element and initiating an action corresponding to said at least        one input element.

In a further aspect the present invention provides a computer system forenabling user input and control of a cursor on a display device via asubstrate having position-coding pattern disposed in or on a surfacethereof, said substrate comprising at least one input element and adiscrete cursor zone, said computer system being configured for:

-   -   receiving interaction data indicative of an interaction of the        sensing device with the substrate, said interaction data being        indicative of a position or movement of the sensing device        relative to the surface;    -   retrieving a page description corresponding to said substrate;    -   determining whether said sensing device is positioned within        said cursor zone;    -   interpreting movement of said sensing device within said cursor        zone as a cursor movement and generating corresponding cursor        control commands for said display device; and    -   otherwise determining if said position or movement of said        sensing device is within a zone of said at least one input        element and initiating an action corresponding to said at least        one input element.

BRIEF DESCRIPTION OF DRAWINGS

Preferred and other embodiments of the invention will now be described,by way of non-limiting example only, with reference to the accompanyingdrawings, in which:

FIG. 1 shows an embodiment of basic netpage architecture;

FIG. 2 is a schematic of a the relationship between a sample printednetpage and its online page description;

FIG. 3 shows an embodiment of basic netpage architecture with variousalternatives for the relay device;

FIG. 3A illustrates a collection of netpage servers, Web terminals,printers and relays interconnected via a network;

FIG. 4 is a schematic view of a high-level structure of a printednetpage and its online page description;

FIG. 5A is a plan view showing a structure of a netpage tag;

FIG. 5B is a plan view showing a relationship between a set of the tagsshown in FIG. 5 a and a field of view of a netpage sensing device in theform of a netpage pen;

FIG. 6A is a plan view showing an alternative structure of a netpagetag;

FIG. 6B is a plan view showing a relationship between a set of the tagsshown in FIG. 6 a and a field of view of a netpage sensing device in theform of a netpage pen;

FIG. 6C is a plan view showing an arrangement of nine of the tags shownin FIG. 6 a where targets are shared between adjacent tags;

FIG. 6D is a plan view showing the interleaving and rotation of thesymbols of the four codewords of the tag shown in FIG. 6 a;

FIG. 7 is a flowchart of a tag image processing and decoding algorithm;

FIG. 8 is a perspective view of a netpage pen and its associatedtag-sensing field-of-view cone;

FIG. 9 is a perspective exploded view of the netpage pen shown in FIG.8;

FIG. 10 is a schematic block diagram of a pen controller for the netpagepen shown in FIGS. 8 and 9;

FIG. 11 is a schematic view of a pen class diagram;

FIG. 12 is a schematic view of a document and page description classdiagram;

FIG. 13 is a schematic view of a document and page ownership classdiagram;

FIG. 14 is a schematic view of a terminal element specialization classdiagram;

FIG. 15 shows cursor control and scroll functions mapped onto anarbitrary page;

FIG. 16 shows an explicit cursor control and scroll page; and

FIG. 17 shows an explicit cursor control, scroll and keyboard page.

DETAILED DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

Note: Memjet™ is a trade mark of Silverbrook Research Pty Ltd,Australia.

In the preferred embodiment, the invention is configured to work withthe netpage networked computer system, a detailed overview of whichfollows. It will be appreciated that not every implementation willnecessarily embody all or even most of the specific details andextensions discussed below in relation to the basic system. However, thesystem is described in its most complete form to reduce the need forexternal reference when attempting to understand the context in whichthe preferred embodiments and aspects of the present invention operate.

In brief summary, the preferred form of the netpage system employs acomputer interface in the form of a mapped surface, that is, a physicalsurface which contains references to a map of the surface maintained ina computer system. The map references can be queried by an appropriatesensing device. Depending upon the specific implementation, the mapreferences may be encoded visibly or invisibly, and defined in such away that a local query on the mapped surface yields an unambiguous mapreference both within the map and among different maps. The computersystem can contain information about features on the mapped surface, andsuch information can be retrieved based on map references supplied by asensing device used with the mapped surface. The information thusretrieved can take the form of actions which are initiated by thecomputer system on behalf of the operator in response to the operator'sinteraction with the surface features.

In its preferred form, the netpage system relies on the production of,and human interaction with, netpages. These are pages of text, graphicsand images printed on ordinary paper, but which work like interactivewebpages. Information is encoded on each page using ink which issubstantially invisible to the unaided human eye. The ink, however, andthereby the coded data, can be sensed by an optically imaging sensingdevice and transmitted to the netpage system. The sensing device maytake the form of a clicker (for clicking on a specific position on asurface), a pointer having a stylus (for pointing or gesturing on asurface using pointer strokes), or a pen having a marking nib (formarking a surface with ink when pointing, gesturing or writing on thesurface). References herein to “pen” or “netpage pen” are provided byway of example only. It will, of course, be appreciated that the pen maytake the form of any of the sensing devices described above.

In one embodiment, active buttons and hyperlinks on each page can beclicked with the sensing device to request information from the networkor to signal preferences to a network server. In one embodiment, textwritten by hand on a netpage is automatically recognized and convertedto computer text in the netpage system, allowing forms to be filled in.In other embodiments, signatures recorded on a netpage are automaticallyverified, allowing e-commerce transactions to be securely authorized. Inother embodiments, text on a netpage may be clicked or gestured toinitiate a search based on keywords indicated by the user.

As illustrated in FIG. 2, a printed netpage 1 can represent ainteractive form which can be filled in by the user both physically, onthe printed page, and “electronically”, via communication between thepen and the netpage system. The example shows a “Request” formcontaining name and address fields and a submit button. The netpageconsists of graphic data 2 printed using visible ink, and coded data 3printed as a collection of tags 4 using invisible ink. The correspondingpage description 5, stored on the netpage network, describes theindividual elements of the netpage. In particular it describes the typeand spatial extent (zone) of each interactive element (i.e. text fieldor button in the example), to allow the netpage system to correctlyinterpret input via the netpage. The submit button 6, for example, has azone 7 which corresponds to the spatial extent of the correspondinggraphic 8.

As illustrated in FIGS. 1 and 3, a netpage sensing device 101, such asthe pen shown in FIGS. 8 and 9 and described in more detail below, worksin conjunction with a netpage relay device 601, which is anInternet-connected device for home, office or mobile use. The pen iswireless and communicates securely with the netpage relay device 601 viaa short-range radio link 9. In an alternative embodiment, the netpagepen 101 utilises a wired connection, such as a USB or other serialconnection, to the relay device 601.

The relay device 601 performs the basic function of relaying interactiondata to a page server 10, which interprets the interaction data. Asshown in FIG. 3, the relay device 601 may, for example, take the form ofa personal computer 601 a, a netpage printer 601 b or some other relay601 c.

The netpage printer 601 b is able to deliver, periodically or on demand,personalized newspapers, magazines, catalogs, brochures and otherpublications, all printed at high quality as interactive netpages.Unlike a personal computer, the netpage printer is an appliance whichcan be, for example, wall-mounted adjacent to an area where the morningnews is first consumed, such as in a user's kitchen, near a breakfasttable, or near the household's point of departure for the day. It alsocomes in tabletop, desktop, portable and miniature versions. Netpagesprinted on-demand at their point of consumption combine the ease-of-useof paper with the timeliness and interactivity of an interactive medium.

Alternatively, the netpage relay device 601 may be a portable device,such as a mobile phone or PDA, a laptop or desktop computer, or aninformation appliance connected to a shared display, such as a TV. Ifthe relay device 601 is not a netpage printer 601 b which printsnetpages digitally and on demand, the netpages may be printed bytraditional analog printing presses, using such techniques as offsetlithography, flexography, screen printing, relief printing androtogravure, as well as by digital printing presses, using techniquessuch as drop-on-demand inkjet, continuous inkjet, dye transfer, andlaser printing.

As shown in FIG. 3, the netpage sensing device 101 interacts with thecoded data on a printed netpage 1, or other printed substrate such as alabel of a product item 251, and communicates, via a short-range radiolink 9, the interaction to the relay 601. The relay 601 sendscorresponding interaction data to the relevant netpage page server 10for interpretation. Raw data received from the sensing device 101 may berelayed directly to the page server 10 as interaction data.Alternatively, the interaction data may be encoded in the form of aninteraction URI and transmitted to the page server 10 via a user's webbrowser. Of course, the relay device 601 (e.g. mobile phone) mayincorporate a web browser and a display device.

Interpretation of the interaction data by the page server 10 may resultin direct access to information requested by the user. This informationmay be sent from the page server 10 to, for example, a user's displaydevice (e.g. a display device associated with the relay device 601). Theinformation sent to the user may be in the form of a webpage constructedby the page server 10 and the webpage may be constructed usinginformation from external web services 200 (e.g. search engines) orlocal web resources accessible by the page server 10. In somecircumstances, the page server 10 may access application computersoftware running on a netpage application server 13.

Alternatively, and as shown explicitly in FIG. 1, a two-step informationretrieval process may be employed. Interaction data is sent from thesensing device 101 to the relay device 601 in the usual way. The relaydevice 601 then sends the interaction data to the page server 10 forinterpretation with reference to the relevant page description 5. Then,the page server 10 forms a request (typically in the form of a requestURI) and sends this request URI back to the user's relay device 601. Aweb browser running on the relay device 601 then sends the request URIto a netpage web server 201, which interprets the request. The netpageweb server 201 may interact with local web resources and external webservices 200 to interpret the request and construct a webpage. Once thewebpage has been constructed by the netpage web server 201, it istransmitted to the web browser running on the user's relay device 601,which typically displays the webpage. This system architecture isparticularly useful for performing searching via netpages, as describedin our earlier U.S. patent application Ser. No. 11/672,950 filed on Feb.8, 2007 (the contents of which is incorporated by reference). Forexample, the request URI may encode search query terms, which aresearched via the netpage web server 201.

The netpage relay device 601 can be configured to support any number ofsensing devices, and a sensing device can work with any number ofnetpage relays. In the preferred implementation, each netpage sensingdevice 101 has a unique identifier. This allows each user to maintain adistinct profile with respect to a netpage page server 10 or applicationserver 13.

Digital, on-demand delivery of netpages 1 may be performed by thenetpage printer 601 b, which exploits the growing availability ofbroadband Internet access. Netpage publication servers 14 on the netpagenetwork are configured to deliver print-quality publications to netpageprinters. Periodical publications are delivered automatically tosubscribing netpage printers via pointcasting and multicasting Internetprotocols. Personalized publications are filtered and formattedaccording to individual user profiles.

A netpage pen may be registered with a netpage registration server 11and linked to one or more payment card accounts. This allows e-commercepayments to be securely authorized using the netpage pen. The netpageregistration server compares the signature captured by the netpage penwith a previously registered signature, allowing it to authenticate theuser's identity to an e-commerce server. Other biometrics can also beused to verify identity. One version of the netpage pen includesfingerprint scanning, verified in a similar way by the netpageregistration server.

Netpage System Architecture

Each object model in the system is described using a Unified ModelingLanguage (UML) class diagram. A class diagram consists of a set ofobject classes connected by relationships, and two kinds ofrelationships are of interest here: associations and generalizations. Anassociation represents some kind of relationship between objects, i.e.between instances of classes. A generalization relates actual classes,and can be understood in the following way: if a class is thought of asthe set of all objects of that class, and class A is a generalization ofclass B, then B is simply a subset of A. The UML does not directlysupport second-order modelling—i.e. classes of classes.

Each class is drawn as a rectangle labelled with the name of the class.It contains a list of the attributes of the class, separated from thename by a horizontal line, and a list of the operations of the class,separated from the attribute list by a horizontal line. In the classdiagrams which follow, however, operations are never modelled.

An association is drawn as a line joining two classes, optionallylabelled at either end with the multiplicity of the association. Thedefault multiplicity is one. An asterisk (*) indicates a multiplicity of“many”, i.e. zero or more. Each association is optionally labelled withits name, and is also optionally labelled at either end with the role ofthe corresponding class. An open diamond indicates an aggregationassociation (“is-part-of”), and is drawn at the aggregator end of theassociation line.

A generalization relationship (“is-a”) is drawn as a solid line joiningtwo classes, with an arrow (in the form of an open triangle) at thegeneralization end.

When a class diagram is broken up into multiple diagrams, any classwhich is duplicated is shown with a dashed outline in all but the maindiagram which defines it. It is shown with attributes only where it isdefined.

1 NETPAGES

Netpages are the foundation on which a netpage network is built. Theyprovide a paper-based user interface to published information andinteractive services.

A netpage consists of a printed page (or other surface region) invisiblytagged with references to an online description of the page. The onlinepage description is maintained persistently by the netpage page server10. The page description describes the visible layout and content of thepage, including text, graphics and images. It also describes the inputelements on the page, including buttons, hyperlinks, and input fields. Anetpage allows markings made with a netpage pen on its surface to besimultaneously captured and processed by the netpage system.

Multiple netpages (for example, those printed by analog printingpresses) can share the same page description. However, to allow inputthrough otherwise identical pages to be distinguished, each netpage maybe assigned a unique page identifier. This page ID has sufficientprecision to distinguish between a very large number of netpages.

Each reference to the page description is encoded in a printed tag. Thetag identifies the unique page on which it appears, and therebyindirectly identifies the page description. The tag also identifies itsown position on the page. Characteristics of the tags are described inmore detail below.

Tags are typically printed in infrared-absorptive ink on any substratewhich is infrared-reflective, such as ordinary paper, or in infraredfluorescing ink. Near-infrared wavelengths are invisible to the humaneye but are easily sensed by a solid-state image sensor with anappropriate filter.

A tag is sensed by a 2D area image sensor in the netpage sensing device,and the tag data is transmitted to the netpage system via the nearestnetpage relay device. The pen is wireless and communicates with thenetpage relay device via a short-range radio link. Tags are sufficientlysmall and densely arranged that the sensing device can reliably image atleast one tag even on a single click on the page. It is important thatthe pen recognize the page ID and position on every interaction with thepage, since the interaction is stateless. Tags are error-correctablyencoded to make them partially tolerant to surface damage.

The netpage page server 10 maintains a unique page instance for eachunique printed netpage, allowing it to maintain a distinct set ofuser-supplied values for input fields in the page description for eachprinted netpage.

The relationship between the page description, the page instance, andthe printed netpage is shown in FIG. 4. The printed netpage may be partof a printed netpage document 45. The page instance may be associatedwith both the netpage printer which printed it and, if known, thenetpage user who requested it.

2 NETPAGE TAGS 2.1 Tag Data Content

In a preferred form, each tag identifies the region in which it appears,and the location of that tag within the region and an orientation of thetag relative to a substrate on which the tag is printed. A tag may alsocontain flags which relate to the region as a whole or to the tag. Oneor more flag bits may, for example, signal a tag sensing device toprovide feedback indicative of a function associated with the immediatearea of the tag, without the sensing device having to refer to adescription of the region. A netpage pen may, for example, illuminate an“active area” LED when in the zone of a hyperlink.

As will be more clearly explained below, in a preferred embodiment, eachtag typically contains an easily recognized invariant structure whichaids initial detection, and which assists in minimizing the effect ofany warp induced by the surface or by the sensing process. The tagspreferably tile the entire page, and are sufficiently small and denselyarranged that the pen can reliably image at least one tag even on asingle click on the page. It is important that the pen recognize thepage ID and position on every interaction with the page, since theinteraction is stateless.

In a preferred embodiment, the region to which a tag refers coincideswith an entire page, and the region ID encoded in the tag is thereforesynonymous with the page ID of the page on which the tag appears. Inother embodiments, the region to which a tag refers can be an arbitrarysubregion of a page or other surface. For example, it can coincide withthe zone of an interactive element, in which case the region ID candirectly identify the interactive element.

TABLE 1 Tag data Field Precision (bits) Page ID/Region ID 100 Tag ID/x-ycoordinates 16 Flags 4 Total 120

Each tag contains 120 bits of information, typically allocated as shownin Table 1. Assuming a maximum tag density of 64 per square inch, a16-bit tag ID supports a region size of up to 1024 square inches. Largerregions can be mapped continuously without increasing the tag IDprecision simply by using abutting regions and maps. The 100-bit regionID allows 2¹⁰⁰ (˜10³⁰ or a million trillion trillion) different regionsto be uniquely identified.

2.2 Tag Data Encoding

The 120 bits of tag data are redundantly encoded using a (15, 5)Reed-Solomon code. This yields 360 encoded bits consisting of 6codewords of 15 4-bit symbols each. The (15, 5) code allows up to 5symbol errors to be corrected per codeword, i.e. it is tolerant of asymbol error rate of up to 33% per codeword.

Each 4-bit symbol is represented in a spatially coherent way in the tag,and the symbols of the six codewords are interleaved spatially withinthe tag. This ensures that a burst error (an error affecting multiplespatially adjacent bits) damages a minimum number of symbols overall anda minimum number of symbols in any one codeword, thus maximising thelikelihood that the burst error can be fully corrected.

Any suitable error-correcting code can be used in place of a (15, 5)Reed-Solomon code, for example a Reed-Solomon code with more or lessredundancy, with the same or different symbol and codeword sizes;another block code; or a different kind of code, such as a convolutionalcode (see, for example, Stephen B. Wicker, Error Control Systems forDigital Communication and Storage, Prentice-Hall 1995, the contents ofwhich a herein incorporated by cross-reference).

2.3 Physical Tag Structure

The physical representation of the tag, shown in FIG. 5 a, includesfixed target structures 15, 16, 17 and variable data areas 18. The fixedtarget structures allow a sensing device such as the netpage pen todetect the tag and infer its three-dimensional orientation relative tothe sensor. The data areas contain representations of the individualbits of the encoded tag data.

To achieve proper tag reproduction, the tag is rendered at a resolutionof 256×256 dots. When printed at 1600 dots per inch this yields a tagwith a diameter of about 4 mm. At this resolution the tag is designed tobe surrounded by a “quiet area” of radius 16 dots. Since the quiet areais also contributed by adjacent tags, it only adds 16 dots to theeffective diameter of the tag.

The tag may include a plurality of target structures. A detection ring15 allows the sensing device to initially detect the tag. The ring iseasy to detect because it is rotationally invariant and because a simplecorrection of its aspect ratio removes most of the effects ofperspective distortion. An orientation axis 16 allows the sensing deviceto determine the approximate planar orientation of the tag due to theyaw of the sensor. The orientation axis is skewed to yield a uniqueorientation. Four perspective targets 17 allow the sensing device toinfer an accurate two-dimensional perspective transform of the tag andhence an accurate three-dimensional position and orientation of the tagrelative to the sensor.

All target structures are redundantly large to improve their immunity tonoise.

In order to support “single-click” interaction with a tagged region viaa sensing device, the sensing device must be able to see at least oneentire tag in its field of view no matter where in the region or at whatorientation it is positioned. The required diameter of the field of viewof the sensing device is therefore a function of the size and spacing ofthe tags.

Thus, if a tag has a circular shape, the minimum diameter of the sensorfield of view is obtained when the tags are tiled on a equilateraltriangular grid, as shown in FIG. 5 b.

2.4 Tag Image Processing and Decoding

The tag image processing and decoding performed by a sensing device suchas the netpage pen is shown in FIG. 7. While a captured image is beingacquired from the image sensor, the dynamic range of the image isdetermined (at 20). The center of the range is then chosen as the binarythreshold for the image 21. The image is then thresholded and segmentedinto connected pixel regions (i.e. shapes 23) (at 22). Shapes which aretoo small to represent tag target structures are discarded. The size andcentroid of each shape is also computed.

Binary shape moments 25 are then computed (at 24) for each shape, andthese provide the basis for subsequently locating target structures.Central shape moments are by their nature invariant of position, and canbe easily made invariant of scale, aspect ratio and rotation.

The ring target structure 15 is the first to be located (at 26). A ringhas the advantage of being very well behaved when perspective-distorted.Matching proceeds by aspect-normalizing and rotation-normalizing eachshape's moments. Once its second-order moments are normalized the ringis easy to recognize even if the perspective distortion was significant.The ring's original aspect and rotation 27 together provide a usefulapproximation of the perspective transform.

The axis target structure 16 is the next to be located (at 28). Matchingproceeds by applying the ring's normalizations to each shape's moments,and rotation-normalizing the resulting moments. Once its second-ordermoments are normalized the axis target is easily recognized. Note thatone third order moment is required to disambiguate the two possibleorientations of the axis. The shape is deliberately skewed to one sideto make this possible. Note also that it is only possible torotation-normalize the axis target after it has had the ring'snormalizations applied, since the perspective distortion can hide theaxis target's axis. The axis target's original rotation provides auseful approximation of the tag's rotation due to pen yaw 29.

The four perspective target structures 17 are the last to be located (at30). Good estimates of their positions are computed based on their knownspatial relationships to the ring and axis targets, the aspect androtation of the ring, and the rotation of the axis. Matching proceeds byapplying the ring's normalizations to each shape's moments. Once theirsecond-order moments are normalized the circular perspective targets areeasy to recognize, and the target closest to each estimated position istaken as a match. The original centroids of the four perspective targetsare then taken to be the perspective-distorted corners 31 of a square ofknown size in tag space, and an eight-degree-of-freedom perspectivetransform 33 is inferred (at 32) based on solving the well-understoodequations relating the four tag-space and image-space point pairs (seeHeckbert, P., Fundamentals of Texture Mapping and Image Warping, MastersThesis, Dept. of EECS, U. of California at Berkeley, Technical ReportNo. UCB/CSD 89/516, June 1989, the contents of which are hereinincorporated by cross-reference).

The inferred tag-space to image-space perspective transform is used toproject (at 36) each known data bit position in tag space into imagespace where the real-valued position is used to bilinearly interpolate(at 36) the four relevant adjacent pixels in the input image. Thepreviously computed image threshold 21 is used to threshold the resultto produce the final bit value 37.

Once all 360 data bits 37 have been obtained in this way, each of thesix 60-bit Reed-Solomon codewords is decoded (at 38) to yield 20 decodedbits 39, or 120 decoded bits in total. Note that the codeword symbolsare sampled in codeword order, so that codewords are implicitlyde-interleaved during the sampling process.

The ring target 15 is only sought in a subarea of the image whoserelationship to the image guarantees that the ring, if found, is part ofa complete tag. If a complete tag is not found and successfully decoded,then no pen position is recorded for the current frame. Given adequateprocessing power and ideally a non-minimal field of view 193, analternative strategy involves seeking another tag in the current image.

The obtained tag data indicates the identity of the region containingthe tag and the position of the tag within the region. An accurateposition 35 of the pen nib in the region, as well as the overallorientation 35 of the pen, is then inferred (at 34) from the perspectivetransform 33 observed on the tag and the known spatial relationshipbetween the image sensor (containing the optical axis of the pen) andthe nib (which typically contains the physical axis of the pen). Theimage sensor is usually offset from the nib.

2.5 Alternative Tag Structures

The tag structure described above is designed to support the tagging ofnon-planar surfaces where a regular tiling of tags may not be possible.In the more usual case of planar surfaces where a regular tiling of tagsis possible, i.e. surfaces such as sheets of paper and the like, moreefficient tag structures can be used which exploit the regular nature ofthe tiling.

FIG. 6 a shows a square tag 4 with four perspective targets 17. The tagrepresents sixty 4-bit Reed-Solomon symbols 47, for a total of 240 bits.The tag represents each one bit as a dot 48, and each zero bit by theabsence of the corresponding dot. The perspective targets are designedto be shared between adjacent tags, as shown in FIGS. 6 b and 6 c. FIG.6 b shows a square tiling of 16 tags and the corresponding minimum fieldof view 193, which must span the diagonals of two tags. FIG. 6 c shows asquare tiling of nine tags, containing all one bits for illustrationpurposes.

Using a (15, 7) Reed-Solomon code, 112 bits of tag data are redundantlyencoded to produce 240 encoded bits. The four codewords are interleavedspatially within the tag to maximize resilience to burst errors.Assuming a 16-bit tag ID as before, this allows a region ID of up to 92bits.

The data-bearing dots 48 of the tag are designed to not overlap theirneighbors, so that groups of tags cannot produce structures whichresemble targets. This also saves ink. The perspective targets thereforeallow detection of the tag, so further targets are not required. Tagimage processing proceeds as described in section 1.2.4 above, with theexception that steps 26 and 28 are omitted.

Although the tag may contain an orientation feature to allowdisambiguation of the four possible orientations of the tag relative tothe sensor, it is also possible to embed orientation data in the tagdata. For example, the four codewords can be arranged so that each tagorientation contains one codeword placed at that orientation, as shownin FIG. 6 d, where each symbol is labelled with the number of itscodeword (1-4) and the position of the symbol within the codeword (A-O).Tag decoding then consists of decoding one codeword at each orientation.Each codeword can either contain a single bit indicating whether it isthe first codeword, or two bits indicating which codeword it is. Thelatter approach has the advantage that if, say, the data content of onlyone codeword is required, then at most two codewords need to be decodedto obtain the desired data. This may be the case if the region ID is notexpected to change within a stroke and is thus only decoded at the startof a stroke. Within a stroke only the codeword containing the tag ID isthen desired. Furthermore, since the rotation of the sensing devicechanges slowly and predictably within a stroke, only one codewordtypically needs to be decoded per frame.

It is possible to dispense with perspective targets altogether andinstead rely on the data representation being self-registering. In thiscase each bit value (or multi-bit value) is typically represented by anexplicit glyph, i.e. no bit value is represented by the absence of aglyph. This ensures that the data grid is well-populated, and thusallows the grid to be reliably identified and its perspective distortiondetected and subsequently corrected during data sampling. To allow tagboundaries to be detected, each tag data must contain a marker pattern,and these must be redundantly encoded to allow reliable detection. Theoverhead of such marker patterns is similar to the overhead of explicitperspective targets. One such scheme uses dots positioned a variouspoints relative to grid vertices to represent different glyphs and hencedifferent multi-bit values (see Anoto Technology Description, AnotoApril 2000).

Additional tag structures are disclosed in U.S. Pat. No. 6,929,186(“Orientation-indicating machine-readable coded data”) filed by theapplicant or assignee of the present invention and the contents of whichis herein incorporated by reference.

2.6 Tag Map

Decoding a tag typically results in a region ID, a tag ID, and atag-relative pen transform. Before the tag ID and the tag-relative penlocation can be translated into an absolute location within the taggedregion, the location of the tag within the region must be known. This isgiven by a tag map, a function which maps each tag ID in a tagged regionto a corresponding location. The tag map class diagram is shown in FIG.22, as part of the netpage printer class diagram.

A tag map reflects the scheme used to tile the surface region with tags,and this can vary according to surface type. When multiple taggedregions share the same tiling scheme and the same tag numbering scheme,they can also share the same tag map.

The tag map for a region must be retrievable via the region ID. Thus,given a region ID, a tag ID and a pen transform, the tag map can beretrieved, the tag ID can be translated into an absolute tag locationwithin the region, and the tag-relative pen location can be added to thetag location to yield an absolute pen location within the region.

The tag ID may have a structure which assists translation through thetag map. It may, for example, encode Cartesian (x-y) coordinates orpolar coordinates, depending on the surface type on which it appears.The tag ID structure is dictated by and known to the tag map, and tagIDs associated with different tag maps may therefore have differentstructures.

With the tagging scheme described above, the tags usually function incooperation with associated visual elements on the netpage. Thesefunction as user interactive elements in that a user can interact withthe printed page using an appropriate sensing device in order for tagdata to be read by the sensing device and for an appropriate response tobe generated in the netpage system.

Additionally (or alternatively), decoding a tag may be used to provideorientation data indicative of the yaw of the pen relative to thesurface. The orientation data may be determined using, for example, theorientation axis 16 described above (Section 2.3) or orientation dataembedded in the tag data (Section 2.5).

3 Document and Page Descriptions

A preferred embodiment of a document and page description class diagramis shown in FIGS. 12 and 13.

In the netpage system a document is described at three levels. At themost abstract level the document 836 has a hierarchical structure whoseterminal elements 839 are associated with content objects 840 such astext objects, text style objects, image objects, etc. Once the documentis printed on a printer with a particular page size, the document ispaginated and otherwise formatted. Formatted terminal elements 835 willin some cases be associated with content objects which are differentfrom those associated with their corresponding terminal elements,particularly where the content objects are style-related. Each printedinstance of a document and page is also described separately, to allowinput captured through a particular page instance 830 to be recordedseparately from input captured through other instances of the same pagedescription.

The presence of the most abstract document description on the pageserver allows a copy of a document to be printed without being forced toaccept the source document's specific format. The user or a printingpress may be requesting a copy for a printer with a different page size,for example. Conversely, the presence of the formatted documentdescription on the page server allows the page server to efficientlyinterpret user actions on a particular printed page.

A formatted document 834 consists of a set of formatted pagedescriptions 5, each of which consists of a set of formatted terminalelements 835. Each formatted element has a spatial extent or zone 58 onthe page. This defines the active area of input elements such ashyperlinks and input fields.

A document instance 831 corresponds to a formatted document 834. Itconsists of a set of page instances 830, each of which corresponds to apage description 5 of the formatted document. Each page instance 830describes a single unique printed netpage 1, and records the page ID 50of the netpage. A page instance is not part of a document instance if itrepresents a copy of a page requested in isolation.

A page instance consists of a set of terminal element instances 832. Anelement instance only exists if it records instance-specificinformation. Thus, a hyperlink instance exists for a hyperlink elementbecause it records a transaction ID 55 which is specific to the pageinstance, and a field instance exists for a field element because itrecords input specific to the page instance. An element instance doesnot exist, however, for static elements such as textflows.

A terminal element 839 can be a visual element or an input element. Avisual element can be a static element 843 or a dynamic element 846. Aninput element may be, for example, a hyperlink element 844 or a fieldelement 845, as shown in FIG. 14. Other types of input element are ofcourse possible, such a input elements, which select a particular modeof the pen 101.

A page instance has a background field 833 which is used to record anydigital ink captured on the page which does not apply to a specificinput element.

In the preferred form of the invention, a tag map 811 is associated witheach page instance to allow tags on the page to be translated intolocations on the page.

4 The Netpage Network

In one embodiment, a netpage network consists of a distributed set ofnetpage page servers 10, netpage registration servers 11, netpage IDservers 12, netpage application servers 13, and netpage relay devices601 connected via a network 19 such as the Internet, as shown in FIG. 3.

The netpage registration server 11 is a server which recordsrelationships between users, pens, printers and applications, andthereby authorizes various network activities. It authenticates usersand acts as a signing proxy on behalf of authenticated users inapplication transactions. It also provides handwriting recognitionservices. As described above, a netpage page server 10 maintainspersistent information about page descriptions and page instances. Thenetpage network includes any number of page servers, each handling asubset of page instances.

Since a page server also maintains user input values for each pageinstance, clients such as netpage relays 601 send netpage input directlyto the appropriate page server. The page server interprets any suchinput relative to the description of the corresponding page.

A netpage ID server 12 allocates document IDs 51 on demand, and providesload-balancing of page servers via its ID allocation scheme.

A netpage relay 601 uses the Internet Distributed Name System (DNS), orsimilar, to resolve a netpage page ID 50 into the network address of thenetpage page server 10 handling the corresponding page instance.

A netpage application server 13 is a server which hosts interactivenetpage applications.

Netpage servers can be hosted on a variety of network server platformsfrom manufacturers such as IBM, Hewlett-Packard, and Sun. Multiplenetpage servers can run concurrently on a single host, and a singleserver can be distributed over a number of hosts. Some or all of thefunctionality provided by netpage servers, and in particular thefunctionality provided by the ID server and the page server, can also beprovided directly in a netpage appliance such as a netpage printer, in acomputer workstation, or on a local network.

5 The Netpage Pen

The active sensing device of the netpage system may take the form of aclicker (for clicking on a specific position on a surface), a pointerhaving a stylus (for pointing or gesturing on a surface using pointerstrokes), or a pen having a marking nib (for marking a surface with inkwhen pointing, gesturing or writing on the surface). A pen 101 isdescribed herein, although it will be appreciated that clickers andpointers may have similar features. The pen 101 uses its embeddedcontroller 134 to capture and decode netpage tags from a page via animage sensor. The image sensor is a solid-state device provided with anappropriate filter to permit sensing at only near-infrared wavelengths.As described in more detail below, the system is able to sense when thenib is in contact with the surface, and the pen is able to sense tags ata sufficient rate to capture human handwriting (i.e. at 200 dpi orgreater and 100 Hz or faster). Information captured by the pen may beencrypted and wirelessly transmitted to the printer (or base station),the printer or base station interpreting the data with respect to the(known) page structure.

The preferred embodiment of the netpage pen 101 operates both as anormal marking ink pen and as a non-marking stylus (i.e. as a pointer).The marking aspect, however, is not necessary for using the netpagesystem as a browsing system, such as when it is used as an Internetinterface. Each netpage pen is registered with the netpage system andhas a unique pen ID 61. FIG. 11 shows the netpage pen class diagram,reflecting pen-related information maintained by a registration server11 on the netpage network.

When the nib is in contact with a netpage, the pen determines itsposition and orientation relative to the page. The nib is attached to aforce sensor, and the force on the nib is interpreted relative to athreshold to indicate whether the pen is “up” or “down”. This allows aninteractive element on the page to be ‘clicked’ by pressing with the pennib, in order to request, say, information from a network. Furthermore,the force may be captured as a continuous value to allow, say, the fulldynamics of a signature to be verified.

The pen determines the position and orientation of its nib on thenetpage by imaging, in the infrared spectrum, an area 193 of the page inthe vicinity of the nib. It decodes the nearest tag and computes theposition of the nib relative to the tag from the observed perspectivedistortion on the imaged tag and the known geometry of the pen optics.Although the position resolution of the tag may be low, because the tagdensity on the page is inversely proportional to the tag size, theadjusted position resolution is quite high, exceeding the minimumresolution required for accurate handwriting recognition.

Pen actions relative to a netpage are captured as a series of strokes. Astroke consists of a sequence of time-stamped pen positions on the page,initiated by a pen-down event and completed by the subsequent pen-upevent. A stroke is also tagged with the page ID 50 of the netpagewhenever the page ID changes, which, under normal circumstances, is atthe commencement of the stroke.

Each netpage pen has a current selection 826 associated with it,allowing the user to perform copy and paste operations etc. Theselection is timestamped to allow the system to discard it after adefined time period. The current selection describes a region of a pageinstance. It consists of the most recent digital ink stroke capturedthrough the pen relative to the background area of the page. It isinterpreted in an application-specific manner once it is submitted to anapplication via a selection hyperlink activation.

Each pen has a current nib 824. This is the nib last notified by the pento the system. In the case of the default netpage pen described above,either the marking black ink nib or the non-marking stylus nib iscurrent. Each pen also has a current nib style 825. This is the nibstyle last associated with the pen by an application, e.g. in responseto the user selecting a color from a palette. The default nib style isthe nib style associated with the current nib. Strokes captured througha pen are tagged with the current nib style. When the strokes aresubsequently reproduced, they are reproduced in the nib style with whichthey are tagged.

The pen 101 may have one or more buttons 209. As described in U.S.application Ser. No. 11/672,950 filed on Feb. 8, 2007 (the contents ofwhich is herein incorporated by reference), the button(s) may be used todetermine a mode or behavior of the pen, which, in turn, determines howa stroke or, more generally, interaction data is interpreted by the pageserver 10.

Whenever the pen is within range of a relay device 601 with which it cancommunicate, the pen slowly flashes its “online” LED. When the pen failsto decode a stroke relative to the page, it momentarily activates its“error” LED. When the pen succeeds in decoding a stroke relative to thepage, it momentarily activates its “ok” LED.

A sequence of captured strokes is referred to as digital ink. Digitalink forms the basis for the digital exchange of drawings andhandwriting, for online recognition of handwriting, and for onlineverification of signatures.

The pen is typically wireless and transmits digital ink to the relaydevice 601 via a short-range radio link. The transmitted digital ink isencrypted for privacy and security and packetized for efficienttransmission, but is always flushed on a pen-up event to ensure timelyhandling in the printer.

When the pen is out-of-range of a relay device 601 it buffers digitalink in internal memory, which has a capacity of over ten minutes ofcontinuous handwriting. When the pen is once again within range of arelay device, it transfers any buffered digital ink.

A pen can be registered with any number of relay devices, but becauseall state data resides in netpages both on paper and on the network, itis largely immaterial which relay device a pen is communicating with atany particular time.

One embodiment of the pen is described in greater detail in Section 7below, with reference to FIGS. 8 to 10.

6 Netpage Interaction

The netpage relay device 601 receives data relating to a stroke from thepen 101 when the pen is used to interact with a netpage 1. The codeddata 3 of the tags 4 is read by the pen when it is used to execute amovement, such as a stroke. The data allows the identity of theparticular page to be determined and an indication of the positioning ofthe pen relative to the page to be obtained. Interaction data, typicallycomprising the page ID 50 and at least one position of the pen, istransmitted to the relay device 601, where it resolves, via the DNS, thepage ID 50 of the stroke into the network address of the netpage pageserver 10 which maintains the corresponding page instance 830. It thentransmits the stroke to the page server. If the page was recentlyidentified in an earlier stroke, then the relay device may already havethe address of the relevant page server in its cache. Each netpageconsists of a compact page layout maintained persistently by a netpagepage server (see below). The page layout refers to objects such asimages, fonts and pieces of text, typically stored elsewhere on thenetpage network.

When the page server receives the stroke from the pen, it retrieves thepage description to which the stroke applies, and determines whichelement of the page description the stroke intersects. It is then ableto interpret the stroke in the context of the type of the relevantelement.

A “click” is a stroke where the distance and time between the pen downposition and the subsequent pen up position are both less than somesmall maximum. An object which is activated by a click typicallyrequires a click to be activated, and accordingly, a longer stroke isignored. The failure of a pen action, such as a “sloppy” click, toregister may be indicated by the lack of response from the pen's “ok”LED.

Hyperlinks and form fields are two kinds of input elements, which may becontained in a netpage page description. Input through a form field canalso trigger the activation of an associated hyperlink. These types ofinput elements are described in further detail in the above-identifiedpatents and patent applications, the contents of which are hereinincorporated by cross-reference.

7 Detailed Netpage Pen Description 7.1 Pen Mechanics

Referring to FIGS. 8 and 9, the pen, generally designated by referencenumeral 101, includes a housing 102 in the form of a plastics mouldinghaving walls 103 defining an interior space 104 for mounting the pencomponents. Mode selector buttons 209 are provided on the housing 102.The pen top 105 is in operation rotatably mounted at one end 106 of thehousing 102. A semi-transparent cover 107 is secured to the opposite end108 of the housing 102. The cover 107 is also of moulded plastics, andis formed from semi-transparent material in order to enable the user toview the status of the LED mounted within the housing 102. The cover 107includes a main part 109 which substantially surrounds the end 108 ofthe housing 102 and a projecting portion 110 which projects back fromthe main part 109 and fits within a corresponding slot 111 formed in thewalls 103 of the housing 102. A radio antenna 112 is mounted behind theprojecting portion 110, within the housing 102. Screw threads 113surrounding an aperture 113A on the cover 107 are arranged to receive ametal end piece 114, including corresponding screw threads 115. Themetal end piece 114 is removable to enable ink cartridge replacement.

Also mounted within the cover 107 is a tri-color status LED 116 on aflex PCB 117. The antenna 112 is also mounted on the flex PCB 117. Thestatus LED 116 is mounted at the top of the pen 101 for good all-aroundvisibility.

The pen can operate both as a normal marking ink pen and as anon-marking stylus. An ink pen cartridge 118 with nib 119 and a stylus120 with stylus nib 121 are mounted side by side within the housing 102.Either the ink cartridge nib 119 or the stylus nib 121 can be broughtforward through open end 122 of the metal end piece 114, by rotation ofthe pen top 105. Respective slider blocks 123 and 124 are mounted to theink cartridge 118 and stylus 120, respectively. A rotatable cam barrel125 is secured to the pen top 105 in operation and arranged to rotatetherewith. The cam barrel 125 includes a cam 126 in the form of a slotwithin the walls 181 of the cam barrel. Cam followers 127 and 128projecting from slider blocks 123 and 124 fit within the cam slot 126.On rotation of the cam barrel 125, the slider blocks 123 or 124 moverelative to each other to project either the pen nib 119 or stylus nib121 out through the hole 122 in the metal end piece 114. The pen 101 hasthree states of operation. By turning the top 105 through 90° steps, thethree states are:

-   -   Stylus 120 nib 121 out;    -   Ink cartridge 118 nib 119 out; and    -   Neither ink cartridge 118 nib 119 out nor stylus 120 nib 121        out.

A second flex PCB 129, is mounted on an electronics chassis 130 whichsits within the housing 102. The second flex PCB 129 mounts an infraredLED 131 for providing infrared radiation for projection onto thesurface. An image sensor 132 is provided mounted on the second flex PCB129 for receiving reflected radiation from the surface. The second flexPCB 129 also mounts a radio frequency chip 133, which includes an RFtransmitter and RF receiver, and a controller chip 134 for controllingoperation of the pen 101. An optics block 135 (formed from moulded clearplastics) sits within the cover 107 and projects an infrared beam ontothe surface and receives images onto the image sensor 132. Power supplywires 136 connect the components on the second flex PCB 129 to batterycontacts 137 which are mounted within the cam barrel 125. A terminal 138connects to the battery contacts 137 and the cam barrel 125. A threevolt rechargeable battery 139 sits within the cam barrel 125 in contactwith the battery contacts. An induction charging coil 140 is mountedabout the second flex PCB 129 to enable recharging of the battery 139via induction. The second flex PCB 129 also mounts an infrared LED 143and infrared photodiode 144 for detecting displacement in the cam barrel125 when either the stylus 120 or the ink cartridge 118 is used forwriting, in order to enable a determination of the force being appliedto the surface by the pen nib 119 or stylus nib 121. The IR photodiode144 detects light from the IR LED 143 via reflectors (not shown) mountedon the slider blocks 123 and 124.

Rubber grip pads 141 and 142 are provided towards the end 108 of thehousing 102 to assist gripping the pen 101, and top 105 also includes aclip 142 for clipping the pen 101 to a pocket.

7.2 Pen Controller

The pen 101 is arranged to determine the position of its nib (stylus nib121 or ink cartridge nib 119) by imaging, in the infrared spectrum, anarea of the surface in the vicinity of the nib. It records the locationdata from the nearest location tag, and is arranged to calculate thedistance of the nib 121 or 119 from the location tab utilising optics135 and controller chip 134. The controller chip 134 calculates theorientation (yaw) of the pen using an orientation indicator in theimaged tag, and the nib-to-tag distance from the perspective distortionobserved on the imaged tag.

Utilising the RF chip 133 and antenna 112 the pen 101 can transmit thedigital ink data (which is encrypted for security and packaged forefficient transmission) to the computing system.

When the pen is in range of a relay device 601, the digital ink data istransmitted as it is formed. When the pen 101 moves out of range,digital ink data is buffered within the pen 101 (the pen 101 circuitryincludes a buffer arranged to store digital ink data for approximately12 minutes of the pen motion on the surface) and can be transmittedlater.

In Applicant's U.S. Pat. No. 6,870,966, the contents of which isincorporated herein by reference, a pen 101 having an interchangeableink cartridge nib and stylus nib was described.

Accordingly, and referring to FIG. 27, when the pen 101 connects to thecomputing system, the controller 134 notifies the system of the pen ID,nib ID 175, current absolute time 176, and the last absolute time itobtained from the system prior to going offline. The pen ID allows thecomputing system to identify the pen when there is more than one penbeing operated with the computing system.

The nib ID allows the computing system to identify which nib (stylus nib121 or ink cartridge nib 119) is presently being used. The computingsystem can vary its operation depending upon which nib is being used.For example, if the ink cartridge nib 119 is being used the computingsystem may defer producing feedback output because immediate feedback isprovided by the ink markings made on the surface. Where the stylus nib121 is being used, the computing system may produce immediate feedbackoutput.

Since a user may change the nib 119, 121 between one stroke and thenext, the pen 101 optionally records a nib ID for a stroke 175. Thisbecomes the nib ID implicitly associated with later strokes.

Cartridges having particular nib characteristics may be interchangeablein the pen. The pen controller 134 may interrogate a cartridge to obtainthe nib ID 175 of the cartridge. The nib ID 175 may be stored in a ROMor a barcode on the cartridge. The controller 134 notifies the system ofthe nib ID whenever it changes. The system is thereby able to determinethe characteristics of the nib used to produce a stroke 175, and isthereby subsequently able to reproduce the characteristics of the strokeitself.

The controller chip 134 is mounted on the second flex PCB 129 in the pen101. FIG. 10 is a block diagram illustrating in more detail thearchitecture of the controller chip 134. FIG. 10 also showsrepresentations of the RF chip 133, the image sensor 132, the tri-colorstatus LED 116, the IR illumination LED 131, the IR force sensor LED143, and the force sensor photodiode 144.

The pen controller chip 134 includes a controlling processor 145. Bus146 enables the exchange of data between components of the controllerchip 134. Flash memory 147 and a 512 KB DRAM 148 are also included. Ananalog-to-digital converter 149 is arranged to convert the analog signalfrom the force sensor photodiode 144 to a digital signal.

An image sensor interface 152 interfaces with the image sensor 132. Atransceiver controller 153 and base band circuit 154 are also includedto interface with the RF chip 133 which includes an RF circuit 155 andRF resonators and inductors 156 connected to the antenna 112.

The controlling processor 145 captures and decodes location data fromtags from the surface via the image sensor 132, monitors the forcesensor photodiode 144, controls the LEDs 116, 131 and 143, and handlesshort-range radio communication via the radio transceiver 153. It is amedium-performance (˜40 MHz) general-purpose RISC processor.

The processor 145, digital transceiver components (transceivercontroller 153 and baseband circuit 154), image sensor interface 152,flash memory 147 and 512 KB DRAM 148 are integrated in a singlecontroller ASIC. Analog RF components (RF circuit 155 and RF resonatorsand inductors 156) are provided in the separate RF chip.

The image sensor is a 215×215 pixel CCD (such a sensor is produced byMatsushita Electronic Corporation, and is described in a paper byItakura, K T Nobusada, N Okusenya, R Nagayoshi, and M Ozaki, “A 1 mm 50k-Pixel IT CCD Image Sensor for Miniature Camera System”, IEEETransactions on Electronic Devices, Volt 47, number 1, January 2000,which is incorporated herein by reference) with an IR filter.

The controller ASIC 134 enters a quiescent state after a period ofinactivity when the pen 101 is not in contact with a surface. Itincorporates a dedicated circuit 150 which monitors the force sensorphotodiode 144 and wakes up the controller 134 via the power manager 151on a pen-down event.

The radio transceiver communicates in the unlicensed 900 MHz bandnormally used by cordless telephones, or alternatively in the unlicensed2.4 GHz industrial, scientific and medical (ISM) band, and usesfrequency hopping and collision detection to provide interference-freecommunication.

In an alternative embodiment, the pen incorporates an Infrared DataAssociation (IrDA) interface for short-range communication with a basestation or netpage printer.

7.3 Alternative Motion Sensor

In a further embodiment, the pen 101 includes a pair of orthogonalaccelerometers mounted in the normal plane of the pen 101 axis. Theaccelerometers 190 are shown in FIGS. 9 and 10 in ghost outline.

The provision of the accelerometers enables this embodiment of the pen101 to sense motion without reference to surface location tags. Eachlocation tag ID can then identify an object of interest rather than aposition on the surface. For example, if the object is a user interfaceinput element (e.g. a command button), then the tag ID of each locationtag within the area of the input element can directly identify the inputelement.

The acceleration measured by the accelerometers in each of the x and ydirections is integrated with respect to time to produce aninstantaneous velocity and position.

Since the starting position of the stroke may not be known, onlyrelative positions within a stroke are calculated. Although positionintegration accumulates errors in the sensed acceleration,accelerometers typically have high resolution, and the time duration ofa stroke, over which errors accumulate, is short.

It will be appreciated that a number of alternative (or additional)motion sensors may be employed in a Netpage pen 101. These typicallyeither measure absolute displacement or relative displacement. Forexample, an optical mouse that measures displacement relative to anexternal grid (see U.S. Pat. No. 4,390,873 and U.S. Pat. No. 4,521,772)measures absolute displacement, whereas a mechanical mouse that measuresdisplacement via the movement of a wheel or ball in contact with thesurface (see U.S. Pat. No. 3,541,541 and U.S. Pat. No. 4,464,652)measures relative displacement because measurement errors accumulate. Anoptical mouse that measures displacement relative to surface texture(see U.S. Pat. No. 6,631,218, U.S. Pat. No. 6,281,882, U.S. Pat. No.6,297,513 and U.S. Pat. No. 4,794,384), measures relative displacementfor the same reason. Motion sensors based on point interferometry (seeU.S. Pat. No. 6,246,482) or acceleration (see U.S. Pat. No. 4,787,051)also measure relative displacement. The contents of all US patentsidentified in the preceding paragraph relating to motion sensors areherein incorporated by reference.

7.4 GUI Control

As discussed in U.S. application Ser. No. 11/672,950 filed on Feb. 8,2007 (the contents of which is herein incorporated by reference), aNetpage pen 101 can be used to generate cursor control commands (i.e.typically mouse events) to allow seamless transitions between paperinteractions and on-screen interactions.

A computer system associated with the display device may receive cursorcontrol data (in the form of relative motion data) directly from the pen101, with the pen performing the necessary processing to generate thecursor control data from the interaction data. Alternatively, thecomputer system may receive interaction data as usual from the pen 101,and then generate cursor control commands for an associated displaydevice. Alternatively, the computer system may be a remote server whichreceives interaction data from the Netpage pen 101 and transmits cursorcontrol commands to a display device near the user (e.g. mobile phone).Any of these system architectures may support cursor control, althoughgeneration of cursor control commands in the pen is generally preferred.

As discussed in U.S. application Ser. No. 11/672,950, a cursor controlbehaviour can be selected in various ways, including via a momentary orpersistent mode switch. Alternatively, cursor control behaviour may alsobe automatically selected in the absence of a Netpage tag pattern, ifthe Netpage pen 101 incorporates a motion sensor that functions in theabsence of a tag pattern.

When positions generated by a Netpage pen 101 are intrinsicallyabsolute, such as when generated at least partially with reference to aNetpage tag pattern, then such positions can be trivially converted intoabsolute cursor control commands. The extent of the physical surfacewith which the sensing device is interacting is ideally mapped to theextent of a display device for the purposes of translating sensingdevice positions into cursor control commands.

However, cursor control commands commonly specify changes in positionrather than absolute positions—i.e. they are relative position changes.Absolute positions generated by a Netpage pen 101 by reading tags 4 maybe trivially converted into relative cursor control commands. Therelative scale of physical displacements of the Netpage reader andcorresponding screen displacements can be specified as a matter of userpreference, as well as whether the mapping is absolute or relative.

Although relative displacements of the pen 101 may be readily calculatedfrom absolute motion data, the implementation of cursor controlbehaviour from absolute positions is problematic in practice. In orderfor cursor control behaviour to appear ‘natural’ from a user'sperspective, cursor movements on a screen should always followsubstantially the movement of the pen 101 i.e. a left pen movement movesthe on-screen cursor to the left, an up pen movement moves the on-screencursor upwards etc. If a surface is orientated in the same way as adisplayed page, then on-screen cursor movements naturally reflectmovement of the pen 101. However, if the surface is upside down, thenthe on-screen cursor movements will be confusing and unnatural for theuser i.e. a left pen movement would move the on-screen cursor to theright.

Since users are not accustomed to orienting their traditional mousepadsin a certain way, they equally would not expect to orient theirNetpage-tagged surface in a certain way in order to invoke naturalcursor-control behaviour. In other words, it is desirable that thesurface and pen 101 should invoke natural mouse behaviour irrespectiveof how the surface is oriented.

This problem is solved by making used of the orientation informationcontained in the Netpage tags 4. As explained above in Sections 2.3 to2.5, the yaw of the pen 101 relative to the surface may be calculated bymaking use of this orientation information. If orientation data as wellas absolute motion data is received by a computer system, then thecomputer system can determine movement of the pen 101 relative to itselfby taking into account the yaw of the pen relative to the surface.Hence, movement of the pen, from a user's perspective, is substantiallytranslated into a corresponding on-screen cursor movement. In this way,the pen 101 may be used to control naturally the movement of the cursor,irrespective of the orientation of the surface.

Of course, when positions generated by a Netpage pen 101 areintrinsically relative, such as when they are generated using a relativemotion sensing mechanism (e.g. accelerometers, mechanical mouse, opticalmouse etc), then they map naturally to relative cursor control commands,again with a (potentially user-specified) scale factor.

Cursor control is a subset of graphical user interface (GUI) input andcontrol in general, including functions such as:

-   -   scrolling    -   web browser back/forward    -   page up/down etc.    -   cut/copy/paste    -   tab between GUI applications    -   launch specific GUI application (word processor, e-mail, web        browser, etc.)    -   volume control (up/down/mute)    -   log off, sleep    -   keyboard entry in general

Scrolling can be supported in the conventional way via a scroll wheel onthe Netpage pen 101. It can also be provided implicitly as part of acursor control behaviour, when motion sensing at least partially occurswith reference to a Netpage tag pattern, by reserving part of the extentof each printed Netpage tag pattern as a scroll region. For example, theright-hand couple of inches of each printed Netpage might be reservedfor vertical scrolling, and the bottom couple of inches might bereserved for horizontal scrolling. This scroll region may be active whenit is determined that the pen 101 is operating in a cursor mode (forexample, by a mode switch on the pen).

Scrolling, like cursor control, can be absolute or relative, and can bespecified as a matter of user preference. As an alternative to separatevertical and horizontal scrolling areas, the dominant direction of theuser's scroll gesture within a single scroll region, relative to theorientation of the tag pattern, can also be used to distinguish verticalfrom horizontal scrolling. In order to allow diagonal scrolling, athreshold can be imposed on the vertical and horizontal components ofthe user's gesture to prevent inadvertent diagonal scrolling. As analternative to reserving a scroll region, one or two scroll modeselection switches can be provided on the pen 101.

FIG. 15 shows cursor control and scrolling functions mapped onto anarbitrary Netpage tagged page. The functions are only operative when theNetpage pen's cursor control behaviour is selected. The user readilylearns from experience that if the pen's cursor control behaviour isselected then cursor control and scrolling actions may be performed viacertain regions of any Netpage, even though there may be no explicitvisual indication of this functionality in the visible content of thepage. For example, scroll regions along a righthand and bottom edgeregion may be standard for any Netpage. These scroll regions would beactive only in the cursor mode.

FIG. 16 shows cursor control and scrolling functions explicitly mappedonto a page with a matching visual layout. Hence, the page shown in FIG.16 is a dedicated cursor control page, specifically tailored for GUIcontrol, including cursor control and scrolling actions. FIG. 17 showscursor control, scrolling functions and keyboard keys explicitly mappedonto a page with a matching visual layout. In the explicitly mappedcases the functions are self-selecting, and so can be operative in anypen behaviour.

Any function or key input can also be generated via a suitable Netpagetagged surface, either via tags specifically coded to indicatecorresponding functions or keys, or via a page description thatindicates corresponding functions or keys in the usual way. The formerhas the advantage that the input can be identified without consultingthe page description 5. This allows the user's relay device 601, whichmay commonly be the user's display device, to capture such input withoutrecourse to the Netpage server 10. In the latter case any function orkey input generated by the server with reference to the page descriptioncan be routed to the user's display device via the netpage architecture(see FIG. 1 and US Patent Publication No. 2006/025175, the contents ofwhich is herein incorporated by reference). This has the advantage thatit supports a display device that is separate from the relay device.

Printed controls can also be provided for selecting one-shot orpersistent modes, such as a scrolling mode. Printed controls may beselected via a typical netpage interaction, whereby a user selects aninteractive control element on a page, and this interaction isinterpreted as a mode selection in the computer system via the pagedescription.

The present invention has been described with reference to a preferredembodiment and number of specific alternative embodiments. However, itwill be appreciated by those skilled in the relevant fields that anumber of other embodiments, differing from those specificallydescribed, will also fall within the spirit and scope of the presentinvention. Accordingly, it will be understood that the invention is notintended to be limited to the specific embodiments described in thepresent specification, including documents incorporated bycross-reference as appropriate. The scope of the invention is onlylimited by the attached claims.

1. A sensing device for interaction with a surface, said sensing devicehaving automatic mode selection, said sensing device comprising: animage sensor for imaging the surface and generating image data; a motionsensor configured for determining one or more relative position changesof the sensing device; a processor configured for: receiving the imagedata; and automatically selecting, using said image data, either aninteraction mode or a cursor mode for said sensing device; andcommunication means for transmitting either interaction data or cursordata to a computer system, dependent on said selected mode, wherein saidprocessor is configured to: select the interaction mode and generateinteraction data from the image data if said image data indicates thatsaid sensing device is interacting with a first surface having aposition-coding pattern disposed thereon, said interaction data beingindicative of at least one absolute location of the sensing devicerelative to the surface; and select the cursor mode if said image dataindicates that said sensing device is interacting with a second surfacelacking a position-coding pattern, said cursor data being indicative ofsaid one or more relative position changes of the sensing device.
 2. Thesensing device of claim 1, wherein the motion sensor is selected fromany one of the group comprising: at least one accelerometer; amechanical mouse; an optical mouse; and a point interferometry device.3. The sensing device of claim 2, wherein said motion sensor is anoptical mouse utilizing at least one of: a pattern-based optical mousetechnique; a texture-based optical mouse technique; and alaser-speckle-based optical mouse technique.
 4. The sensing device ofclaim 1, wherein the position-coding pattern of the first surface isindicative of a plurality of locations on the surface and of an identityof a region.
 5. The sensing device of 4, wherein, in said interactionmode, said processor is configured for determining the identity of theregion using the imaged position-coding pattern, and said interactiondata is further indicative of the identity of the region.
 6. The sensingdevice of claim 4, wherein the identity of the region is coincident withan identity of the surface.
 7. The method of claim 1, wherein theposition-coding pattern is comprised of a plurality of tags, each tagidentifying the identity of the surface and a location of the tag on thesurface.
 8. A system for initiating an action corresponding tointeraction of a sensing device relative to a surface, said systemcomprising: (A) the sensing device comprising: an image sensor forimaging the surface and generating image data; a motion sensorconfigured for determining one or more relative position changes of thesensing device; a processor configured for: receiving the image data;and automatically selecting, using said image data, either aninteraction mode or a cursor mode for said sensing device; andcommunication means for transmitting either interaction data or cursordata to a computer system, dependent on said selected mode, wherein saidprocessor is configured to: select the interaction mode and generateinteraction data if said image data indicates that said sensing deviceis interacting with a first surface having a position-coding patterndisposed thereon, said interaction data being indicative of an absolutelocation of the sensing device relative to the surface; and select thecursor mode if said image data indicates that said sensing device isinteracting with a second surface lacking a position-coding pattern,said cursor data being indicative of said one or more relative positionchanges of the sensing device; and (B) the computer system configuredfor: receiving the interaction data and the cursor data from the sensingdevice; interpreting said interaction data to initiate an actioncorresponding to said interaction with said surface; and interpretingsaid cursor data to control movement of a cursor on a display device. 9.The system of claim 8, wherein said action initiated by said interactiondata is selected from at least one of: hyperlinking; form-filling;searching; and content-extraction.
 10. The system of claim 8, whereinthe position-coding pattern of the first surface is indicative of aplurality of locations on the surface and of an identity of a region.11. The system of 10, wherein, in said interaction mode, said processoris configured for determining the identity of the region using theimaged position-coding pattern, and said interaction data is furtherindicative of the identity of the region.
 12. The system of claim 11,wherein said computer system is configured to interpret said interactiondata by the steps of: identifying and retrieving a page descriptioncorresponding to the first surface using the identity of the region;determining a request using the retrieved page description and theinteraction data; and initiating an action based on said request. 13.The sensing device of claim 10, wherein the identity of the region iscoincident with an identity of the surface.
 14. The method of claim 8,wherein the position-coding pattern is comprised of a plurality of tags,each tag identifying the identity of the surface and a location of thetag on the surface.
 15. The system of claim 8, wherein display device isselected from at least one of: a display device associated with thecomputer system a display device integral with the computer system; anda display device remote from the computer system.
 16. A method ofautomatically selecting a mode of a sensing device interacting with asurface, said sensing device comprising a motion sensor configured fordetermining one or more relative position changes of the sensing device,said method comprising the steps of: imaging the surface and generatingimage data; automatically selecting, using said image data, either aninteraction mode or a cursor mode for said sensing device; andtransmitting either interaction data or cursor data to a computersystem, dependent on said selected mode, wherein: the interaction modeis selected and the interaction data is generated from the image data ifsaid image data indicates that said sensing device is interacting with afirst surface having a position-coding pattern disposed thereon, saidinteraction data being indicative of at least one absolute location ofthe sensing device relative to the surface; and the cursor mode isselected and one or more relative position changes of the sensing deviceare determined if said image data indicates that said sensing device isinteracting with a second surface lacking a position-coding pattern,said cursor data being indicative of said one or more relative positionchanges of the sensing device.
 17. The method of claim 16, furthercomprising the steps of: receiving the interaction data in the computersystem; and interpreting said interaction data to initiate an actioncorresponding to said interaction with said surface.
 18. The method ofclaim 16, further comprising the steps of: receiving the cursor datafrom the sensing device; interpreting said cursor data to controlmovement of a cursor on a display device.